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	/*
	* Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.util;

	import java.util.function.Consumer;
	import java.util.function.Predicate;
	import java.util.function.UnaryOperator;
	import jdk.internal.access.SharedSecrets;
	import jdk.internal.util.ArraysSupport;

	/**
	* Resizable-array implementation of the {@code List} interface. Implements
	* all optional list operations, and permits all elements, including
	* {@code null}. In addition to implementing the {@code List} interface,
	* this class provides methods to manipulate the size of the array that is
	* used internally to store the list. (This class is roughly equivalent to
	* {@code Vector}, except that it is unsynchronized.)
	*
	* <p>The {@code size}, {@code isEmpty}, {@code get}, {@code set},
	* {@code iterator}, and {@code listIterator} operations run in constant
	* time. The {@code add} operation runs in <i>amortized constant time</i>,
	* that is, adding n elements requires O(n) time. All of the other operations
	* run in linear time (roughly speaking). The constant factor is low compared
	* to that for the {@code LinkedList} implementation.
	*
	* <p>Each {@code ArrayList} instance has a <i>capacity</i>. The capacity is
	* the size of the array used to store the elements in the list. It is always
	* at least as large as the list size. As elements are added to an ArrayList,
	* its capacity grows automatically. The details of the growth policy are not
	* specified beyond the fact that adding an element has constant amortized
	* time cost.
	*
	* <p>An application can increase the capacity of an {@code ArrayList} instance
	* before adding a large number of elements using the {@code ensureCapacity}
	* operation. This may reduce the amount of incremental reallocation.
	*
	* <p><strong>Note that this implementation is not synchronized.</strong>
	* If multiple threads access an {@code ArrayList} instance concurrently,
	* and at least one of the threads modifies the list structurally, it
	* <i>must</i> be synchronized externally. (A structural modification is
	* any operation that adds or deletes one or more elements, or explicitly
	* resizes the backing array; merely setting the value of an element is not
	* a structural modification.) This is typically accomplished by
	* synchronizing on some object that naturally encapsulates the list.
	*
	* If no such object exists, the list should be "wrapped" using the
	* {@link Collections#synchronizedList Collections.synchronizedList}
	* method. This is best done at creation time, to prevent accidental
	* unsynchronized access to the list:<pre>
	* List list = Collections.synchronizedList(new ArrayList(...));</pre>
	*
	* <p id="fail-fast">
	* The iterators returned by this class's {@link #iterator() iterator} and
	* {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>:
	* if the list is structurally modified at any time after the iterator is
	* created, in any way except through the iterator's own
	* {@link ListIterator#remove() remove} or
	* {@link ListIterator#add(Object) add} methods, the iterator will throw a
	* {@link ConcurrentModificationException}. Thus, in the face of
	* concurrent modification, the iterator fails quickly and cleanly, rather
	* than risking arbitrary, non-deterministic behavior at an undetermined
	* time in the future.
	*
	* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
	* as it is, generally speaking, impossible to make any hard guarantees in the
	* presence of unsynchronized concurrent modification. Fail-fast iterators
	* throw {@code ConcurrentModificationException} on a best-effort basis.
	* Therefore, it would be wrong to write a program that depended on this
	* exception for its correctness: <i>the fail-fast behavior of iterators
	* should be used only to detect bugs.</i>
	*
	* <p>This class is a member of the
	* <a href="{@docRoot}/java.base/java/util/package-summary.html#CollectionsFramework">
	* Java Collections Framework</a>.
	*
	* @param <E> the type of elements in this list
	*
	* @author Josh Bloch
	* @author Neal Gafter
	* @see Collection
	* @see List
	* @see LinkedList
	* @see Vector
	* @since 1.2
	*/
	public class ArrayList<E> extends AbstractList<E>
	implements List<E>, RandomAccess, Cloneable, java.io.Serializable
	{
	@java.io.Serial
	private static final long serialVersionUID = 8683452581122892189L;

	/**
	* Default initial capacity.
	*/
	private static final int DEFAULT_CAPACITY = 10;

	/**
	* Shared empty array instance used for empty instances.
	*/
	private static final Object[] EMPTY_ELEMENTDATA = {};

	/**
	* Shared empty array instance used for default sized empty instances. We
	* distinguish this from EMPTY_ELEMENTDATA to know how much to inflate when
	* first element is added.
	*/
	private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {};

	/**
	* The array buffer into which the elements of the ArrayList are stored.
	* The capacity of the ArrayList is the length of this array buffer. Any
	* empty ArrayList with elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA
	* will be expanded to DEFAULT_CAPACITY when the first element is added.
	*/
	transient Object[] elementData; // non-private to simplify nested class access

	/**
	* The size of the ArrayList (the number of elements it contains).
	*
	* @serial
	*/
	private int size;

	/**
	* Constructs an empty list with the specified initial capacity.
	*
	* @param initialCapacity the initial capacity of the list
	* @throws IllegalArgumentException if the specified initial capacity
	* is negative
	*/
	public ArrayList(int initialCapacity) {
	if (initialCapacity > 0) {
	this.elementData = new Object[initialCapacity];
	} else if (initialCapacity == 0) {
	this.elementData = EMPTY_ELEMENTDATA;
	} else {
	throw new IllegalArgumentException("Illegal Capacity: "+
	initialCapacity);
	}
	}

	/**
	* Constructs an empty list with an initial capacity of ten.
	*/
	public ArrayList() {
	this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA;
	}

	/**
	* Constructs a list containing the elements of the specified
	* collection, in the order they are returned by the collection's
	* iterator.
	*
	* @param c the collection whose elements are to be placed into this list
	* @throws NullPointerException if the specified collection is null
	*/
	public ArrayList(Collection<? extends E> c) {
	Object[] a = c.toArray();
	if ((size = a.length) != 0) {
	if (c.getClass() == ArrayList.class) {
	elementData = a;
	} else {
	elementData = Arrays.copyOf(a, size, Object[].class);
	}
	} else {
	// replace with empty array.
	elementData = EMPTY_ELEMENTDATA;
	}
	}

	/**
	* Trims the capacity of this {@code ArrayList} instance to be the
	* list's current size. An application can use this operation to minimize
	* the storage of an {@code ArrayList} instance.
	*/
	public void trimToSize() {
	modCount++;
	if (size < elementData.length) {
	elementData = (size == 0)
	? EMPTY_ELEMENTDATA
	: Arrays.copyOf(elementData, size);
	}
	}

	/**
	* Increases the capacity of this {@code ArrayList} instance, if
	* necessary, to ensure that it can hold at least the number of elements
	* specified by the minimum capacity argument.
	*
	* @param minCapacity the desired minimum capacity
	*/
	public void ensureCapacity(int minCapacity) {
	if (minCapacity > elementData.length
	&& !(elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA
	&& minCapacity <= DEFAULT_CAPACITY)) {
	modCount++;
	grow(minCapacity);
	}
	}

	/**
	* Increases the capacity to ensure that it can hold at least the
	* number of elements specified by the minimum capacity argument.
	*
	* @param minCapacity the desired minimum capacity
	* @throws OutOfMemoryError if minCapacity is less than zero
	*/
	private Object[] grow(int minCapacity) {
	int oldCapacity = elementData.length;
	if (oldCapacity > 0 \|\| elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {
	int newCapacity = ArraysSupport.newLength(oldCapacity,
	minCapacity - oldCapacity, /* minimum growth */
	oldCapacity >> 1 /* preferred growth */);
	return elementData = Arrays.copyOf(elementData, newCapacity);
	} else {
	return elementData = new Object[Math.max(DEFAULT_CAPACITY, minCapacity)];
	}
	}

	private Object[] grow() {
	return grow(size + 1);
	}

	/**
	* Returns the number of elements in this list.
	*
	* @return the number of elements in this list
	*/
	public int size() {
	return size;
	}

	/**
	* Returns {@code true} if this list contains no elements.
	*
	* @return {@code true} if this list contains no elements
	*/
	public boolean isEmpty() {
	return size == 0;
	}

	/**
	* Returns {@code true} if this list contains the specified element.
	* More formally, returns {@code true} if and only if this list contains
	* at least one element {@code e} such that
	* {@code Objects.equals(o, e)}.
	*
	* @param o element whose presence in this list is to be tested
	* @return {@code true} if this list contains the specified element
	*/
	public boolean contains(Object o) {
	return indexOf(o) >= 0;
	}

	/**
	* Returns the index of the first occurrence of the specified element
	* in this list, or -1 if this list does not contain the element.
	* More formally, returns the lowest index {@code i} such that
	* {@code Objects.equals(o, get(i))},
	* or -1 if there is no such index.
	*/
	public int indexOf(Object o) {
	return indexOfRange(o, 0, size);
	}

	int indexOfRange(Object o, int start, int end) {
	Object[] es = elementData;
	if (o == null) {
	for (int i = start; i < end; i++) {
	if (es[i] == null) {
	return i;
	}
	}
	} else {
	for (int i = start; i < end; i++) {
	if (o.equals(es[i])) {
	return i;
	}
	}
	}
	return -1;
	}

	/**
	* Returns the index of the last occurrence of the specified element
	* in this list, or -1 if this list does not contain the element.
	* More formally, returns the highest index {@code i} such that
	* {@code Objects.equals(o, get(i))},
	* or -1 if there is no such index.
	*/
	public int lastIndexOf(Object o) {
	return lastIndexOfRange(o, 0, size);
	}

	int lastIndexOfRange(Object o, int start, int end) {
	Object[] es = elementData;
	if (o == null) {
	for (int i = end - 1; i >= start; i--) {
	if (es[i] == null) {
	return i;
	}
	}
	} else {
	for (int i = end - 1; i >= start; i--) {
	if (o.equals(es[i])) {
	return i;
	}
	}
	}
	return -1;
	}

	/**
	* Returns a shallow copy of this {@code ArrayList} instance. (The
	* elements themselves are not copied.)
	*
	* @return a clone of this {@code ArrayList} instance
	*/
	public Object clone() {
	try {
	ArrayList<?> v = (ArrayList<?>) super.clone();
	v.elementData = Arrays.copyOf(elementData, size);
	v.modCount = 0;
	return v;
	} catch (CloneNotSupportedException e) {
	// this shouldn't happen, since we are Cloneable
	throw new InternalError(e);
	}
	}

	/**
	* Returns an array containing all of the elements in this list
	* in proper sequence (from first to last element).
	*
	* <p>The returned array will be "safe" in that no references to it are
	* maintained by this list. (In other words, this method must allocate
	* a new array). The caller is thus free to modify the returned array.
	*
	* <p>This method acts as bridge between array-based and collection-based
	* APIs.
	*
	* @return an array containing all of the elements in this list in
	* proper sequence
	*/
	public Object[] toArray() {
	return Arrays.copyOf(elementData, size);
	}

	/**
	* Returns an array containing all of the elements in this list in proper
	* sequence (from first to last element); the runtime type of the returned
	* array is that of the specified array. If the list fits in the
	* specified array, it is returned therein. Otherwise, a new array is
	* allocated with the runtime type of the specified array and the size of
	* this list.
	*
	* <p>If the list fits in the specified array with room to spare
	* (i.e., the array has more elements than the list), the element in
	* the array immediately following the end of the collection is set to
	* {@code null}. (This is useful in determining the length of the
	* list <i>only</i> if the caller knows that the list does not contain
	* any null elements.)
	*
	* @param a the array into which the elements of the list are to
	* be stored, if it is big enough; otherwise, a new array of the
	* same runtime type is allocated for this purpose.
	* @return an array containing the elements of the list
	* @throws ArrayStoreException if the runtime type of the specified array
	* is not a supertype of the runtime type of every element in
	* this list
	* @throws NullPointerException if the specified array is null
	*/
	@SuppressWarnings("unchecked")
	public <T> T[] toArray(T[] a) {
	if (a.length < size)
	// Make a new array of a's runtime type, but my contents:
	return (T[]) Arrays.copyOf(elementData, size, a.getClass());
	System.arraycopy(elementData, 0, a, 0, size);
	if (a.length > size)
	a[size] = null;
	return a;
	}

	// Positional Access Operations

	@SuppressWarnings("unchecked")
	E elementData(int index) {
	return (E) elementData[index];
	}

	@SuppressWarnings("unchecked")
	static <E> E elementAt(Object[] es, int index) {
	return (E) es[index];
	}

	/**
	* Returns the element at the specified position in this list.
	*
	* @param index index of the element to return
	* @return the element at the specified position in this list
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	public E get(int index) {
	Objects.checkIndex(index, size);
	return elementData(index);
	}

	/**
	* Replaces the element at the specified position in this list with
	* the specified element.
	*
	* @param index index of the element to replace
	* @param element element to be stored at the specified position
	* @return the element previously at the specified position
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	public E set(int index, E element) {
	Objects.checkIndex(index, size);
	E oldValue = elementData(index);
	elementData[index] = element;
	return oldValue;
	}

	/**
	* This helper method split out from add(E) to keep method
	* bytecode size under 35 (the -XX:MaxInlineSize default value),
	* which helps when add(E) is called in a C1-compiled loop.
	*/
	private void add(E e, Object[] elementData, int s) {
	if (s == elementData.length)
	elementData = grow();
	elementData[s] = e;
	size = s + 1;
	}

	/**
	* Appends the specified element to the end of this list.
	*
	* @param e element to be appended to this list
	* @return {@code true} (as specified by {@link Collection#add})
	*/
	public boolean add(E e) {
	modCount++;
	add(e, elementData, size);
	return true;
	}

	/**
	* Inserts the specified element at the specified position in this
	* list. Shifts the element currently at that position (if any) and
	* any subsequent elements to the right (adds one to their indices).
	*
	* @param index index at which the specified element is to be inserted
	* @param element element to be inserted
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	public void add(int index, E element) {
	rangeCheckForAdd(index);
	modCount++;
	final int s;
	Object[] elementData;
	if ((s = size) == (elementData = this.elementData).length)
	elementData = grow();
	System.arraycopy(elementData, index,
	elementData, index + 1,
	s - index);
	elementData[index] = element;
	size = s + 1;
	}

	/**
	* Removes the element at the specified position in this list.
	* Shifts any subsequent elements to the left (subtracts one from their
	* indices).
	*
	* @param index the index of the element to be removed
	* @return the element that was removed from the list
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	public E remove(int index) {
	Objects.checkIndex(index, size);
	final Object[] es = elementData;

	@SuppressWarnings("unchecked") E oldValue = (E) es[index];
	fastRemove(es, index);

	return oldValue;
	}

	/**
	* {@inheritDoc}
	*/
	public boolean equals(Object o) {
	if (o == this) {
	return true;
	}

	if (!(o instanceof List)) {
	return false;
	}

	final int expectedModCount = modCount;
	// ArrayList can be subclassed and given arbitrary behavior, but we can
	// still deal with the common case where o is ArrayList precisely
	boolean equal = (o.getClass() == ArrayList.class)
	? equalsArrayList((ArrayList<?>) o)
	: equalsRange((List<?>) o, 0, size);

	checkForComodification(expectedModCount);
	return equal;
	}

	boolean equalsRange(List<?> other, int from, int to) {
	final Object[] es = elementData;
	if (to > es.length) {
	throw new ConcurrentModificationException();
	}
	var oit = other.iterator();
	for (; from < to; from++) {
	if (!oit.hasNext() \|\| !Objects.equals(es[from], oit.next())) {
	return false;
	}
	}
	return !oit.hasNext();
	}

	private boolean equalsArrayList(ArrayList<?> other) {
	final int otherModCount = other.modCount;
	final int s = size;
	boolean equal;
	if (equal = (s == other.size)) {
	final Object[] otherEs = other.elementData;
	final Object[] es = elementData;
	if (s > es.length \|\| s > otherEs.length) {
	throw new ConcurrentModificationException();
	}
	for (int i = 0; i < s; i++) {
	if (!Objects.equals(es[i], otherEs[i])) {
	equal = false;
	break;
	}
	}
	}
	other.checkForComodification(otherModCount);
	return equal;
	}

	private void checkForComodification(final int expectedModCount) {
	if (modCount != expectedModCount) {
	throw new ConcurrentModificationException();
	}
	}

	/**
	* {@inheritDoc}
	*/
	public int hashCode() {
	int expectedModCount = modCount;
	int hash = hashCodeRange(0, size);
	checkForComodification(expectedModCount);
	return hash;
	}

	int hashCodeRange(int from, int to) {
	final Object[] es = elementData;
	if (to > es.length) {
	throw new ConcurrentModificationException();
	}
	int hashCode = 1;
	for (int i = from; i < to; i++) {
	Object e = es[i];
	hashCode = 31 * hashCode + (e == null ? 0 : e.hashCode());
	}
	return hashCode;
	}

	/**
	* Removes the first occurrence of the specified element from this list,
	* if it is present. If the list does not contain the element, it is
	* unchanged. More formally, removes the element with the lowest index
	* {@code i} such that
	* {@code Objects.equals(o, get(i))}
	* (if such an element exists). Returns {@code true} if this list
	* contained the specified element (or equivalently, if this list
	* changed as a result of the call).
	*
	* @param o element to be removed from this list, if present
	* @return {@code true} if this list contained the specified element
	*/
	public boolean remove(Object o) {
	final Object[] es = elementData;
	final int size = this.size;
	int i = 0;
	found: {
	if (o == null) {
	for (; i < size; i++)
	if (es[i] == null)
	break found;
	} else {
	for (; i < size; i++)
	if (o.equals(es[i]))
	break found;
	}
	return false;
	}
	fastRemove(es, i);
	return true;
	}

	/**
	* Private remove method that skips bounds checking and does not
	* return the value removed.
	*/
	private void fastRemove(Object[] es, int i) {
	modCount++;
	final int newSize;
	if ((newSize = size - 1) > i)
	System.arraycopy(es, i + 1, es, i, newSize - i);
	es[size = newSize] = null;
	}

	/**
	* Removes all of the elements from this list. The list will
	* be empty after this call returns.
	*/
	public void clear() {
	modCount++;
	final Object[] es = elementData;
	for (int to = size, i = size = 0; i < to; i++)
	es[i] = null;
	}

	/**
	* Appends all of the elements in the specified collection to the end of
	* this list, in the order that they are returned by the
	* specified collection's Iterator. The behavior of this operation is
	* undefined if the specified collection is modified while the operation
	* is in progress. (This implies that the behavior of this call is
	* undefined if the specified collection is this list, and this
	* list is nonempty.)
	*
	* @param c collection containing elements to be added to this list
	* @return {@code true} if this list changed as a result of the call
	* @throws NullPointerException if the specified collection is null
	*/
	public boolean addAll(Collection<? extends E> c) {
	Object[] a = c.toArray();
	modCount++;
	int numNew = a.length;
	if (numNew == 0)
	return false;
	Object[] elementData;
	final int s;
	if (numNew > (elementData = this.elementData).length - (s = size))
	elementData = grow(s + numNew);
	System.arraycopy(a, 0, elementData, s, numNew);
	size = s + numNew;
	return true;
	}

	/**
	* Inserts all of the elements in the specified collection into this
	* list, starting at the specified position. Shifts the element
	* currently at that position (if any) and any subsequent elements to
	* the right (increases their indices). The new elements will appear
	* in the list in the order that they are returned by the
	* specified collection's iterator.
	*
	* @param index index at which to insert the first element from the
	* specified collection
	* @param c collection containing elements to be added to this list
	* @return {@code true} if this list changed as a result of the call
	* @throws IndexOutOfBoundsException {@inheritDoc}
	* @throws NullPointerException if the specified collection is null
	*/
	public boolean addAll(int index, Collection<? extends E> c) {
	rangeCheckForAdd(index);

	Object[] a = c.toArray();
	modCount++;
	int numNew = a.length;
	if (numNew == 0)
	return false;
	Object[] elementData;
	final int s;
	if (numNew > (elementData = this.elementData).length - (s = size))
	elementData = grow(s + numNew);

	int numMoved = s - index;
	if (numMoved > 0)
	System.arraycopy(elementData, index,
	elementData, index + numNew,
	numMoved);
	System.arraycopy(a, 0, elementData, index, numNew);
	size = s + numNew;
	return true;
	}

	/**
	* Removes from this list all of the elements whose index is between
	* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive.
	* Shifts any succeeding elements to the left (reduces their index).
	* This call shortens the list by {@code (toIndex - fromIndex)} elements.
	* (If {@code toIndex==fromIndex}, this operation has no effect.)
	*
	* @throws IndexOutOfBoundsException if {@code fromIndex} or
	* {@code toIndex} is out of range
	* ({@code fromIndex < 0 \|\|
	* toIndex > size() \|\|
	* toIndex < fromIndex})
	*/
	protected void removeRange(int fromIndex, int toIndex) {
	if (fromIndex > toIndex) {
	throw new IndexOutOfBoundsException(
	outOfBoundsMsg(fromIndex, toIndex));
	}
	modCount++;
	shiftTailOverGap(elementData, fromIndex, toIndex);
	}

	/** Erases the gap from lo to hi, by sliding down following elements. */
	private void shiftTailOverGap(Object[] es, int lo, int hi) {
	System.arraycopy(es, hi, es, lo, size - hi);
	for (int to = size, i = (size -= hi - lo); i < to; i++)
	es[i] = null;
	}

	/**
	* A version of rangeCheck used by add and addAll.
	*/
	private void rangeCheckForAdd(int index) {
	if (index > size \|\| index < 0)
	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
	}

	/**
	* Constructs an IndexOutOfBoundsException detail message.
	* Of the many possible refactorings of the error handling code,
	* this "outlining" performs best with both server and client VMs.
	*/
	private String outOfBoundsMsg(int index) {
	return "Index: "+index+", Size: "+size;
	}

	/**
	* A version used in checking (fromIndex > toIndex) condition
	*/
	private static String outOfBoundsMsg(int fromIndex, int toIndex) {
	return "From Index: " + fromIndex + " > To Index: " + toIndex;
	}

	/**
	* Removes from this list all of its elements that are contained in the
	* specified collection.
	*
	* @param c collection containing elements to be removed from this list
	* @return {@code true} if this list changed as a result of the call
	* @throws ClassCastException if the class of an element of this list
	* is incompatible with the specified collection
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if this list contains a null element and the
	* specified collection does not permit null elements
	* (<a href="Collection.html#optional-restrictions">optional</a>),
	* or if the specified collection is null
	* @see Collection#contains(Object)
	*/
	public boolean removeAll(Collection<?> c) {
	return batchRemove(c, false, 0, size);
	}

	/**
	* Retains only the elements in this list that are contained in the
	* specified collection. In other words, removes from this list all
	* of its elements that are not contained in the specified collection.
	*
	* @param c collection containing elements to be retained in this list
	* @return {@code true} if this list changed as a result of the call
	* @throws ClassCastException if the class of an element of this list
	* is incompatible with the specified collection
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if this list contains a null element and the
	* specified collection does not permit null elements
	* (<a href="Collection.html#optional-restrictions">optional</a>),
	* or if the specified collection is null
	* @see Collection#contains(Object)
	*/
	public boolean retainAll(Collection<?> c) {
	return batchRemove(c, true, 0, size);
	}

	boolean batchRemove(Collection<?> c, boolean complement,
	final int from, final int end) {
	Objects.requireNonNull(c);
	final Object[] es = elementData;
	int r;
	// Optimize for initial run of survivors
	for (r = from;; r++) {
	if (r == end)
	return false;
	if (c.contains(es[r]) != complement)
	break;
	}
	int w = r++;
	try {
	for (Object e; r < end; r++)
	if (c.contains(e = es[r]) == complement)
	es[w++] = e;
	} catch (Throwable ex) {
	// Preserve behavioral compatibility with AbstractCollection,
	// even if c.contains() throws.
	System.arraycopy(es, r, es, w, end - r);
	w += end - r;
	throw ex;
	} finally {
	modCount += end - w;
	shiftTailOverGap(es, w, end);
	}
	return true;
	}

	/**
	* Saves the state of the {@code ArrayList} instance to a stream
	* (that is, serializes it).
	*
	* @param s the stream
	* @throws java.io.IOException if an I/O error occurs
	* @serialData The length of the array backing the {@code ArrayList}
	* instance is emitted (int), followed by all of its elements
	* (each an {@code Object}) in the proper order.
	*/
	@java.io.Serial
	private void writeObject(java.io.ObjectOutputStream s)
	throws java.io.IOException {
	// Write out element count, and any hidden stuff
	int expectedModCount = modCount;
	s.defaultWriteObject();

	// Write out size as capacity for behavioral compatibility with clone()
	s.writeInt(size);

	// Write out all elements in the proper order.
	for (int i=0; i<size; i++) {
	s.writeObject(elementData[i]);
	}

	if (modCount != expectedModCount) {
	throw new ConcurrentModificationException();
	}
	}

	/**
	* Reconstitutes the {@code ArrayList} instance from a stream (that is,
	* deserializes it).
	* @param s the stream
	* @throws ClassNotFoundException if the class of a serialized object
	* could not be found
	* @throws java.io.IOException if an I/O error occurs
	*/
	@java.io.Serial
	private void readObject(java.io.ObjectInputStream s)
	throws java.io.IOException, ClassNotFoundException {

	// Read in size, and any hidden stuff
	s.defaultReadObject();

	// Read in capacity
	s.readInt(); // ignored

	if (size > 0) {
	// like clone(), allocate array based upon size not capacity
	SharedSecrets.getJavaObjectInputStreamAccess().checkArray(s, Object[].class, size);
	Object[] elements = new Object[size];

	// Read in all elements in the proper order.
	for (int i = 0; i < size; i++) {
	elements[i] = s.readObject();
	}

	elementData = elements;
	} else if (size == 0) {
	elementData = EMPTY_ELEMENTDATA;
	} else {
	throw new java.io.InvalidObjectException("Invalid size: " + size);
	}
	}

	/**
	* Returns a list iterator over the elements in this list (in proper
	* sequence), starting at the specified position in the list.
	* The specified index indicates the first element that would be
	* returned by an initial call to {@link ListIterator#next next}.
	* An initial call to {@link ListIterator#previous previous} would
	* return the element with the specified index minus one.
	*
	* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
	*
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	public ListIterator<E> listIterator(int index) {
	rangeCheckForAdd(index);
	return new ListItr(index);
	}

	/**
	* Returns a list iterator over the elements in this list (in proper
	* sequence).
	*
	* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
	*
	* @see #listIterator(int)
	*/
	public ListIterator<E> listIterator() {
	return new ListItr(0);
	}

	/**
	* Returns an iterator over the elements in this list in proper sequence.
	*
	* <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
	*
	* @return an iterator over the elements in this list in proper sequence
	*/
	public Iterator<E> iterator() {
	return new Itr();
	}

	/**
	* An optimized version of AbstractList.Itr
	*/
	private class Itr implements Iterator<E> {
	int cursor; // index of next element to return
	int lastRet = -1; // index of last element returned; -1 if no such
	int expectedModCount = modCount;

	// prevent creating a synthetic constructor
	Itr() {}

	public boolean hasNext() {
	return cursor != size;
	}

	@SuppressWarnings("unchecked")
	public E next() {
	checkForComodification();
	int i = cursor;
	if (i >= size)
	throw new NoSuchElementException();
	Object[] elementData = ArrayList.this.elementData;
	if (i >= elementData.length)
	throw new ConcurrentModificationException();
	cursor = i + 1;
	return (E) elementData[lastRet = i];
	}

	public void remove() {
	if (lastRet < 0)
	throw new IllegalStateException();
	checkForComodification();

	try {
	ArrayList.this.remove(lastRet);
	cursor = lastRet;
	lastRet = -1;
	expectedModCount = modCount;
	} catch (IndexOutOfBoundsException ex) {
	throw new ConcurrentModificationException();
	}
	}

	@Override
	public void forEachRemaining(Consumer<? super E> action) {
	Objects.requireNonNull(action);
	final int size = ArrayList.this.size;
	int i = cursor;
	if (i < size) {
	final Object[] es = elementData;
	if (i >= es.length)
	throw new ConcurrentModificationException();
	for (; i < size && modCount == expectedModCount; i++)
	action.accept(elementAt(es, i));
	// update once at end to reduce heap write traffic
	cursor = i;
	lastRet = i - 1;
	checkForComodification();
	}
	}

	final void checkForComodification() {
	if (modCount != expectedModCount)
	throw new ConcurrentModificationException();
	}
	}

	/**
	* An optimized version of AbstractList.ListItr
	*/
	private class ListItr extends Itr implements ListIterator<E> {
	ListItr(int index) {
	super();
	cursor = index;
	}

	public boolean hasPrevious() {
	return cursor != 0;
	}

	public int nextIndex() {
	return cursor;
	}

	public int previousIndex() {
	return cursor - 1;
	}

	@SuppressWarnings("unchecked")
	public E previous() {
	checkForComodification();
	int i = cursor - 1;
	if (i < 0)
	throw new NoSuchElementException();
	Object[] elementData = ArrayList.this.elementData;
	if (i >= elementData.length)
	throw new ConcurrentModificationException();
	cursor = i;
	return (E) elementData[lastRet = i];
	}

	public void set(E e) {
	if (lastRet < 0)
	throw new IllegalStateException();
	checkForComodification();

	try {
	ArrayList.this.set(lastRet, e);
	} catch (IndexOutOfBoundsException ex) {
	throw new ConcurrentModificationException();
	}
	}

	public void add(E e) {
	checkForComodification();

	try {
	int i = cursor;
	ArrayList.this.add(i, e);
	cursor = i + 1;
	lastRet = -1;
	expectedModCount = modCount;
	} catch (IndexOutOfBoundsException ex) {
	throw new ConcurrentModificationException();
	}
	}
	}

	/**
	* Returns a view of the portion of this list between the specified
	* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. (If
	* {@code fromIndex} and {@code toIndex} are equal, the returned list is
	* empty.) The returned list is backed by this list, so non-structural
	* changes in the returned list are reflected in this list, and vice-versa.
	* The returned list supports all of the optional list operations.
	*
	* <p>This method eliminates the need for explicit range operations (of
	* the sort that commonly exist for arrays). Any operation that expects
	* a list can be used as a range operation by passing a subList view
	* instead of a whole list. For example, the following idiom
	* removes a range of elements from a list:
	* <pre>
	* list.subList(from, to).clear();
	* </pre>
	* Similar idioms may be constructed for {@link #indexOf(Object)} and
	* {@link #lastIndexOf(Object)}, and all of the algorithms in the
	* {@link Collections} class can be applied to a subList.
	*
	* <p>The semantics of the list returned by this method become undefined if
	* the backing list (i.e., this list) is <i>structurally modified</i> in
	* any way other than via the returned list. (Structural modifications are
	* those that change the size of this list, or otherwise perturb it in such
	* a fashion that iterations in progress may yield incorrect results.)
	*
	* @throws IndexOutOfBoundsException {@inheritDoc}
	* @throws IllegalArgumentException {@inheritDoc}
	*/
	public List<E> subList(int fromIndex, int toIndex) {
	subListRangeCheck(fromIndex, toIndex, size);
	return new SubList<>(this, fromIndex, toIndex);
	}

	private static class SubList<E> extends AbstractList<E> implements RandomAccess {
	private final ArrayList<E> root;
	private final SubList<E> parent;
	private final int offset;
	private int size;

	/**
	* Constructs a sublist of an arbitrary ArrayList.
	*/
	public SubList(ArrayList<E> root, int fromIndex, int toIndex) {
	this.root = root;
	this.parent = null;
	this.offset = fromIndex;
	this.size = toIndex - fromIndex;
	this.modCount = root.modCount;
	}

	/**
	* Constructs a sublist of another SubList.
	*/
	private SubList(SubList<E> parent, int fromIndex, int toIndex) {
	this.root = parent.root;
	this.parent = parent;
	this.offset = parent.offset + fromIndex;
	this.size = toIndex - fromIndex;
	this.modCount = parent.modCount;
	}

	public E set(int index, E element) {
	Objects.checkIndex(index, size);
	checkForComodification();
	E oldValue = root.elementData(offset + index);
	root.elementData[offset + index] = element;
	return oldValue;
	}

	public E get(int index) {
	Objects.checkIndex(index, size);
	checkForComodification();
	return root.elementData(offset + index);
	}

	public int size() {
	checkForComodification();
	return size;
	}

	public void add(int index, E element) {
	rangeCheckForAdd(index);
	checkForComodification();
	root.add(offset + index, element);
	updateSizeAndModCount(1);
	}

	public E remove(int index) {
	Objects.checkIndex(index, size);
	checkForComodification();
	E result = root.remove(offset + index);
	updateSizeAndModCount(-1);
	return result;
	}

	protected void removeRange(int fromIndex, int toIndex) {
	checkForComodification();
	root.removeRange(offset + fromIndex, offset + toIndex);
	updateSizeAndModCount(fromIndex - toIndex);
	}

	public boolean addAll(Collection<? extends E> c) {
	return addAll(this.size, c);
	}

	public boolean addAll(int index, Collection<? extends E> c) {
	rangeCheckForAdd(index);
	int cSize = c.size();
	if (cSize==0)
	return false;
	checkForComodification();
	root.addAll(offset + index, c);
	updateSizeAndModCount(cSize);
	return true;
	}

	public void replaceAll(UnaryOperator<E> operator) {
	root.replaceAllRange(operator, offset, offset + size);
	}

	public boolean removeAll(Collection<?> c) {
	return batchRemove(c, false);
	}

	public boolean retainAll(Collection<?> c) {
	return batchRemove(c, true);
	}

	private boolean batchRemove(Collection<?> c, boolean complement) {
	checkForComodification();
	int oldSize = root.size;
	boolean modified =
	root.batchRemove(c, complement, offset, offset + size);
	if (modified)
	updateSizeAndModCount(root.size - oldSize);
	return modified;
	}

	public boolean removeIf(Predicate<? super E> filter) {
	checkForComodification();
	int oldSize = root.size;
	boolean modified = root.removeIf(filter, offset, offset + size);
	if (modified)
	updateSizeAndModCount(root.size - oldSize);
	return modified;
	}

	public Object[] toArray() {
	checkForComodification();
	return Arrays.copyOfRange(root.elementData, offset, offset + size);
	}

	@SuppressWarnings("unchecked")
	public <T> T[] toArray(T[] a) {
	checkForComodification();
	if (a.length < size)
	return (T[]) Arrays.copyOfRange(
	root.elementData, offset, offset + size, a.getClass());
	System.arraycopy(root.elementData, offset, a, 0, size);
	if (a.length > size)
	a[size] = null;
	return a;
	}

	public boolean equals(Object o) {
	if (o == this) {
	return true;
	}

	if (!(o instanceof List)) {
	return false;
	}

	boolean equal = root.equalsRange((List<?>)o, offset, offset + size);
	checkForComodification();
	return equal;
	}

	public int hashCode() {
	int hash = root.hashCodeRange(offset, offset + size);
	checkForComodification();
	return hash;
	}

	public int indexOf(Object o) {
	int index = root.indexOfRange(o, offset, offset + size);
	checkForComodification();
	return index >= 0 ? index - offset : -1;
	}

	public int lastIndexOf(Object o) {
	int index = root.lastIndexOfRange(o, offset, offset + size);
	checkForComodification();
	return index >= 0 ? index - offset : -1;
	}

	public boolean contains(Object o) {
	return indexOf(o) >= 0;
	}

	public Iterator<E> iterator() {
	return listIterator();
	}

	public ListIterator<E> listIterator(int index) {
	checkForComodification();
	rangeCheckForAdd(index);

	return new ListIterator<E>() {
	int cursor = index;
	int lastRet = -1;
	int expectedModCount = SubList.this.modCount;

	public boolean hasNext() {
	return cursor != SubList.this.size;
	}

	@SuppressWarnings("unchecked")
	public E next() {
	checkForComodification();
	int i = cursor;
	if (i >= SubList.this.size)
	throw new NoSuchElementException();
	Object[] elementData = root.elementData;
	if (offset + i >= elementData.length)
	throw new ConcurrentModificationException();
	cursor = i + 1;
	return (E) elementData[offset + (lastRet = i)];
	}

	public boolean hasPrevious() {
	return cursor != 0;
	}

	@SuppressWarnings("unchecked")
	public E previous() {
	checkForComodification();
	int i = cursor - 1;
	if (i < 0)
	throw new NoSuchElementException();
	Object[] elementData = root.elementData;
	if (offset + i >= elementData.length)
	throw new ConcurrentModificationException();
	cursor = i;
	return (E) elementData[offset + (lastRet = i)];
	}

	public void forEachRemaining(Consumer<? super E> action) {
	Objects.requireNonNull(action);
	final int size = SubList.this.size;
	int i = cursor;
	if (i < size) {
	final Object[] es = root.elementData;
	if (offset + i >= es.length)
	throw new ConcurrentModificationException();
	for (; i < size && root.modCount == expectedModCount; i++)
	action.accept(elementAt(es, offset + i));
	// update once at end to reduce heap write traffic
	cursor = i;
	lastRet = i - 1;
	checkForComodification();
	}
	}

	public int nextIndex() {
	return cursor;
	}

	public int previousIndex() {
	return cursor - 1;
	}

	public void remove() {
	if (lastRet < 0)
	throw new IllegalStateException();
	checkForComodification();

	try {
	SubList.this.remove(lastRet);
	cursor = lastRet;
	lastRet = -1;
	expectedModCount = SubList.this.modCount;
	} catch (IndexOutOfBoundsException ex) {
	throw new ConcurrentModificationException();
	}
	}

	public void set(E e) {
	if (lastRet < 0)
	throw new IllegalStateException();
	checkForComodification();

	try {
	root.set(offset + lastRet, e);
	} catch (IndexOutOfBoundsException ex) {
	throw new ConcurrentModificationException();
	}
	}

	public void add(E e) {
	checkForComodification();

	try {
	int i = cursor;
	SubList.this.add(i, e);
	cursor = i + 1;
	lastRet = -1;
	expectedModCount = SubList.this.modCount;
	} catch (IndexOutOfBoundsException ex) {
	throw new ConcurrentModificationException();
	}
	}

	final void checkForComodification() {
	if (root.modCount != expectedModCount)
	throw new ConcurrentModificationException();
	}
	};
	}

	public List<E> subList(int fromIndex, int toIndex) {
	subListRangeCheck(fromIndex, toIndex, size);
	return new SubList<>(this, fromIndex, toIndex);
	}

	private void rangeCheckForAdd(int index) {
	if (index < 0 \|\| index > this.size)
	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
	}

	private String outOfBoundsMsg(int index) {
	return "Index: "+index+", Size: "+this.size;
	}

	private void checkForComodification() {
	if (root.modCount != modCount)
	throw new ConcurrentModificationException();
	}

	private void updateSizeAndModCount(int sizeChange) {
	SubList<E> slist = this;
	do {
	slist.size += sizeChange;
	slist.modCount = root.modCount;
	slist = slist.parent;
	} while (slist != null);
	}

	public Spliterator<E> spliterator() {
	checkForComodification();

	// ArrayListSpliterator not used here due to late-binding
	return new Spliterator<E>() {
	private int index = offset; // current index, modified on advance/split
	private int fence = -1; // -1 until used; then one past last index
	private int expectedModCount; // initialized when fence set

	private int getFence() { // initialize fence to size on first use
	int hi; // (a specialized variant appears in method forEach)
	if ((hi = fence) < 0) {
	expectedModCount = modCount;
	hi = fence = offset + size;
	}
	return hi;
	}

	public ArrayList<E>.ArrayListSpliterator trySplit() {
	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
	// ArrayListSpliterator can be used here as the source is already bound
	return (lo >= mid) ? null : // divide range in half unless too small
	root.new ArrayListSpliterator(lo, index = mid, expectedModCount);
	}

	public boolean tryAdvance(Consumer<? super E> action) {
	Objects.requireNonNull(action);
	int hi = getFence(), i = index;
	if (i < hi) {
	index = i + 1;
	@SuppressWarnings("unchecked") E e = (E)root.elementData[i];
	action.accept(e);
	if (root.modCount != expectedModCount)
	throw new ConcurrentModificationException();
	return true;
	}
	return false;
	}

	public void forEachRemaining(Consumer<? super E> action) {
	Objects.requireNonNull(action);
	int i, hi, mc; // hoist accesses and checks from loop
	ArrayList<E> lst = root;
	Object[] a;
	if ((a = lst.elementData) != null) {
	if ((hi = fence) < 0) {
	mc = modCount;
	hi = offset + size;
	}
	else
	mc = expectedModCount;
	if ((i = index) >= 0 && (index = hi) <= a.length) {
	for (; i < hi; ++i) {
	@SuppressWarnings("unchecked") E e = (E) a[i];
	action.accept(e);
	}
	if (lst.modCount == mc)
	return;
	}
	}
	throw new ConcurrentModificationException();
	}

	public long estimateSize() {
	return getFence() - index;
	}

	public int characteristics() {
	return Spliterator.ORDERED \| Spliterator.SIZED \| Spliterator.SUBSIZED;
	}
	};
	}
	}

	/**
	* @throws NullPointerException {@inheritDoc}
	*/
	@Override
	public void forEach(Consumer<? super E> action) {
	Objects.requireNonNull(action);
	final int expectedModCount = modCount;
	final Object[] es = elementData;
	final int size = this.size;
	for (int i = 0; modCount == expectedModCount && i < size; i++)
	action.accept(elementAt(es, i));
	if (modCount != expectedModCount)
	throw new ConcurrentModificationException();
	}

	/**
	* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em>
	* and <em>fail-fast</em> {@link Spliterator} over the elements in this
	* list.
	*
	* <p>The {@code Spliterator} reports {@link Spliterator#SIZED},
	* {@link Spliterator#SUBSIZED}, and {@link Spliterator#ORDERED}.
	* Overriding implementations should document the reporting of additional
	* characteristic values.
	*
	* @return a {@code Spliterator} over the elements in this list
	* @since 1.8
	*/
	@Override
	public Spliterator<E> spliterator() {
	return new ArrayListSpliterator(0, -1, 0);
	}

	/** Index-based split-by-two, lazily initialized Spliterator */
	final class ArrayListSpliterator implements Spliterator<E> {

	/*
	* If ArrayLists were immutable, or structurally immutable (no
	* adds, removes, etc), we could implement their spliterators
	* with Arrays.spliterator. Instead we detect as much
	* interference during traversal as practical without
	* sacrificing much performance. We rely primarily on
	* modCounts. These are not guaranteed to detect concurrency
	* violations, and are sometimes overly conservative about
	* within-thread interference, but detect enough problems to
	* be worthwhile in practice. To carry this out, we (1) lazily
	* initialize fence and expectedModCount until the latest
	* point that we need to commit to the state we are checking
	* against; thus improving precision. (This doesn't apply to
	* SubLists, that create spliterators with current non-lazy
	* values). (2) We perform only a single
	* ConcurrentModificationException check at the end of forEach
	* (the most performance-sensitive method). When using forEach
	* (as opposed to iterators), we can normally only detect
	* interference after actions, not before. Further
	* CME-triggering checks apply to all other possible
	* violations of assumptions for example null or too-small
	* elementData array given its size(), that could only have
	* occurred due to interference. This allows the inner loop
	* of forEach to run without any further checks, and
	* simplifies lambda-resolution. While this does entail a
	* number of checks, note that in the common case of
	* list.stream().forEach(a), no checks or other computation
	* occur anywhere other than inside forEach itself. The other
	* less-often-used methods cannot take advantage of most of
	* these streamlinings.
	*/

	private int index; // current index, modified on advance/split
	private int fence; // -1 until used; then one past last index
	private int expectedModCount; // initialized when fence set

	/** Creates new spliterator covering the given range. */
	ArrayListSpliterator(int origin, int fence, int expectedModCount) {
	this.index = origin;
	this.fence = fence;
	this.expectedModCount = expectedModCount;
	}

	private int getFence() { // initialize fence to size on first use
	int hi; // (a specialized variant appears in method forEach)
	if ((hi = fence) < 0) {
	expectedModCount = modCount;
	hi = fence = size;
	}
	return hi;
	}

	public ArrayListSpliterator trySplit() {
	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
	return (lo >= mid) ? null : // divide range in half unless too small
	new ArrayListSpliterator(lo, index = mid, expectedModCount);
	}

	public boolean tryAdvance(Consumer<? super E> action) {
	if (action == null)
	throw new NullPointerException();
	int hi = getFence(), i = index;
	if (i < hi) {
	index = i + 1;
	@SuppressWarnings("unchecked") E e = (E)elementData[i];
	action.accept(e);
	if (modCount != expectedModCount)
	throw new ConcurrentModificationException();
	return true;
	}
	return false;
	}

	public void forEachRemaining(Consumer<? super E> action) {
	int i, hi, mc; // hoist accesses and checks from loop
	Object[] a;
	if (action == null)
	throw new NullPointerException();
	if ((a = elementData) != null) {
	if ((hi = fence) < 0) {
	mc = modCount;
	hi = size;
	}
	else
	mc = expectedModCount;
	if ((i = index) >= 0 && (index = hi) <= a.length) {
	for (; i < hi; ++i) {
	@SuppressWarnings("unchecked") E e = (E) a[i];
	action.accept(e);
	}
	if (modCount == mc)
	return;
	}
	}
	throw new ConcurrentModificationException();
	}

	public long estimateSize() {
	return getFence() - index;
	}

	public int characteristics() {
	return Spliterator.ORDERED \| Spliterator.SIZED \| Spliterator.SUBSIZED;
	}
	}

	// A tiny bit set implementation

	private static long[] nBits(int n) {
	return new long[((n - 1) >> 6) + 1];
	}
	private static void setBit(long[] bits, int i) {
	bits[i >> 6] \|= 1L << i;
	}
	private static boolean isClear(long[] bits, int i) {
	return (bits[i >> 6] & (1L << i)) == 0;
	}

	/**
	* @throws NullPointerException {@inheritDoc}
	*/
	@Override
	public boolean removeIf(Predicate<? super E> filter) {
	return removeIf(filter, 0, size);
	}

	/**
	* Removes all elements satisfying the given predicate, from index
	* i (inclusive) to index end (exclusive).
	*/
	boolean removeIf(Predicate<? super E> filter, int i, final int end) {
	Objects.requireNonNull(filter);
	int expectedModCount = modCount;
	final Object[] es = elementData;
	// Optimize for initial run of survivors
	for (; i < end && !filter.test(elementAt(es, i)); i++)
	;
	// Tolerate predicates that reentrantly access the collection for
	// read (but writers still get CME), so traverse once to find
	// elements to delete, a second pass to physically expunge.
	if (i < end) {
	final int beg = i;
	final long[] deathRow = nBits(end - beg);
	deathRow[0] = 1L; // set bit 0
	for (i = beg + 1; i < end; i++)
	if (filter.test(elementAt(es, i)))
	setBit(deathRow, i - beg);
	if (modCount != expectedModCount)
	throw new ConcurrentModificationException();
	modCount++;
	int w = beg;
	for (i = beg; i < end; i++)
	if (isClear(deathRow, i - beg))
	es[w++] = es[i];
	shiftTailOverGap(es, w, end);
	return true;
	} else {
	if (modCount != expectedModCount)
	throw new ConcurrentModificationException();
	return false;
	}
	}

	@Override
	public void replaceAll(UnaryOperator<E> operator) {
	replaceAllRange(operator, 0, size);
	// TODO(8203662): remove increment of modCount from ...
	modCount++;
	}

	private void replaceAllRange(UnaryOperator<E> operator, int i, int end) {
	Objects.requireNonNull(operator);
	final int expectedModCount = modCount;
	final Object[] es = elementData;
	for (; modCount == expectedModCount && i < end; i++)
	es[i] = operator.apply(elementAt(es, i));
	if (modCount != expectedModCount)
	throw new ConcurrentModificationException();
	}

	@Override
	@SuppressWarnings("unchecked")
	public void sort(Comparator<? super E> c) {
	final int expectedModCount = modCount;
	Arrays.sort((E[]) elementData, 0, size, c);
	if (modCount != expectedModCount)
	throw new ConcurrentModificationException();
	modCount++;
	}

	void checkInvariants() {
	// assert size >= 0;
	// assert size == elementData.length \|\| elementData[size] == null;
	}
	}

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