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	/*
	* Copyright (c) 1997, 2017, 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 sun.misc.SharedSecrets;

	/**
	* Resizable-array implementation of the <tt>List</tt> interface. Implements
	* all optional list operations, and permits all elements, including
	* <tt>null</tt>. In addition to implementing the <tt>List</tt> 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
	* <tt>Vector</tt>, except that it is unsynchronized.)
	*
	* <p>The <tt>size</tt>, <tt>isEmpty</tt>, <tt>get</tt>, <tt>set</tt>,
	* <tt>iterator</tt>, and <tt>listIterator</tt> operations run in constant
	* time. The <tt>add</tt> 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 <tt>LinkedList</tt> implementation.
	*
	* <p>Each <tt>ArrayList</tt> 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 <tt>ArrayList</tt> instance
	* before adding a large number of elements using the <tt>ensureCapacity</tt>
	* operation. This may reduce the amount of incremental reallocation.
	*
	* <p><strong>Note that this implementation is not synchronized.</strong>
	* If multiple threads access an <tt>ArrayList</tt> 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><a name="fail-fast">
	* The iterators returned by this class's {@link #iterator() iterator} and
	* {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>:</a>
	* 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}/../technotes/guides/collections/index.html">
	* Java Collections Framework</a>.
	*
	* @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
	{
	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 <tt>ArrayList</tt> instance to be the
	* list's current size. An application can use this operation to minimize
	* the storage of an <tt>ArrayList</tt> instance.
	*/
	public void trimToSize() {
	modCount++;
	if (size < elementData.length) {
	elementData = (size == 0)
	? EMPTY_ELEMENTDATA
	: Arrays.copyOf(elementData, size);
	}
	}

	/**
	* Increases the capacity of this <tt>ArrayList</tt> 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) {
	int minExpand = (elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA)
	// any size if not default element table
	? 0
	// larger than default for default empty table. It's already
	// supposed to be at default size.
	: DEFAULT_CAPACITY;

	if (minCapacity > minExpand) {
	ensureExplicitCapacity(minCapacity);
	}
	}

	private static int calculateCapacity(Object[] elementData, int minCapacity) {
	if (elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {
	return Math.max(DEFAULT_CAPACITY, minCapacity);
	}
	return minCapacity;
	}

	private void ensureCapacityInternal(int minCapacity) {
	ensureExplicitCapacity(calculateCapacity(elementData, minCapacity));
	}

	private void ensureExplicitCapacity(int minCapacity) {
	modCount++;

	// overflow-conscious code
	if (minCapacity - elementData.length > 0)
	grow(minCapacity);
	}

	/**
	* The maximum size of array to allocate.
	* Some VMs reserve some header words in an array.
	* Attempts to allocate larger arrays may result in
	* OutOfMemoryError: Requested array size exceeds VM limit
	*/
	private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;

	/**
	* 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
	*/
	private void grow(int minCapacity) {
	// overflow-conscious code
	int oldCapacity = elementData.length;
	int newCapacity = oldCapacity + (oldCapacity >> 1);
	if (newCapacity - minCapacity < 0)
	newCapacity = minCapacity;
	if (newCapacity - MAX_ARRAY_SIZE > 0)
	newCapacity = hugeCapacity(minCapacity);
	// minCapacity is usually close to size, so this is a win:
	elementData = Arrays.copyOf(elementData, newCapacity);
	}

	private static int hugeCapacity(int minCapacity) {
	if (minCapacity < 0) // overflow
	throw new OutOfMemoryError();
	return (minCapacity > MAX_ARRAY_SIZE) ?
	Integer.MAX_VALUE :
	MAX_ARRAY_SIZE;
	}

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

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

	/**
	* Returns <tt>true</tt> if this list contains the specified element.
	* More formally, returns <tt>true</tt> if and only if this list contains
	* at least one element <tt>e</tt> such that
	* <tt>(o==null ? e==null : o.equals(e))</tt>.
	*
	* @param o element whose presence in this list is to be tested
	* @return <tt>true</tt> 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 <tt>i</tt> such that
	* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
	* or -1 if there is no such index.
	*/
	public int indexOf(Object o) {
	if (o == null) {
	for (int i = 0; i < size; i++)
	if (elementData[i]==null)
	return i;
	} else {
	for (int i = 0; i < size; i++)
	if (o.equals(elementData[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 <tt>i</tt> such that
	* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
	* or -1 if there is no such index.
	*/
	public int lastIndexOf(Object o) {
	if (o == null) {
	for (int i = size-1; i >= 0; i--)
	if (elementData[i]==null)
	return i;
	} else {
	for (int i = size-1; i >= 0; i--)
	if (o.equals(elementData[i]))
	return i;
	}
	return -1;
	}

	/**
	* Returns a shallow copy of this <tt>ArrayList</tt> instance. (The
	* elements themselves are not copied.)
	*
	* @return a clone of this <tt>ArrayList</tt> 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
	* <tt>null</tt>. (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];
	}

	/**
	* 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) {
	rangeCheck(index);

	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) {
	rangeCheck(index);

	E oldValue = elementData(index);
	elementData[index] = element;
	return oldValue;
	}

	/**
	* Appends the specified element to the end of this list.
	*
	* @param e element to be appended to this list
	* @return <tt>true</tt> (as specified by {@link Collection#add})
	*/
	public boolean add(E e) {
	ensureCapacityInternal(size + 1); // Increments modCount!!
	elementData[size++] = e;
	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);

	ensureCapacityInternal(size + 1); // Increments modCount!!
	System.arraycopy(elementData, index, elementData, index + 1,
	size - index);
	elementData[index] = element;
	size++;
	}

	/**
	* 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) {
	rangeCheck(index);

	modCount++;
	E oldValue = elementData(index);

	int numMoved = size - index - 1;
	if (numMoved > 0)
	System.arraycopy(elementData, index+1, elementData, index,
	numMoved);
	elementData[--size] = null; // clear to let GC do its work

	return oldValue;
	}

	/**
	* 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
	* <tt>i</tt> such that
	* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>
	* (if such an element exists). Returns <tt>true</tt> 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 <tt>true</tt> if this list contained the specified element
	*/
	public boolean remove(Object o) {
	if (o == null) {
	for (int index = 0; index < size; index++)
	if (elementData[index] == null) {
	fastRemove(index);
	return true;
	}
	} else {
	for (int index = 0; index < size; index++)
	if (o.equals(elementData[index])) {
	fastRemove(index);
	return true;
	}
	}
	return false;
	}

	/*
	* Private remove method that skips bounds checking and does not
	* return the value removed.
	*/
	private void fastRemove(int index) {
	modCount++;
	int numMoved = size - index - 1;
	if (numMoved > 0)
	System.arraycopy(elementData, index+1, elementData, index,
	numMoved);
	elementData[--size] = null; // clear to let GC do its work
	}

	/**
	* Removes all of the elements from this list. The list will
	* be empty after this call returns.
	*/
	public void clear() {
	modCount++;

	// clear to let GC do its work
	for (int i = 0; i < size; i++)
	elementData[i] = null;

	size = 0;
	}

	/**
	* 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 <tt>true</tt> 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();
	int numNew = a.length;
	ensureCapacityInternal(size + numNew); // Increments modCount
	System.arraycopy(a, 0, elementData, size, numNew);
	size += numNew;
	return numNew != 0;
	}

	/**
	* 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 <tt>true</tt> 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();
	int numNew = a.length;
	ensureCapacityInternal(size + numNew); // Increments modCount

	int numMoved = size - index;
	if (numMoved > 0)
	System.arraycopy(elementData, index, elementData, index + numNew,
	numMoved);

	System.arraycopy(a, 0, elementData, index, numNew);
	size += numNew;
	return numNew != 0;
	}

	/**
	* 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 \|\|
	* fromIndex >= size() \|\|
	* toIndex > size() \|\|
	* toIndex < fromIndex})
	*/
	protected void removeRange(int fromIndex, int toIndex) {
	modCount++;
	int numMoved = size - toIndex;
	System.arraycopy(elementData, toIndex, elementData, fromIndex,
	numMoved);

	// clear to let GC do its work
	int newSize = size - (toIndex-fromIndex);
	for (int i = newSize; i < size; i++) {
	elementData[i] = null;
	}
	size = newSize;
	}

	/**
	* Checks if the given index is in range. If not, throws an appropriate
	* runtime exception. This method does not check if the index is
	* negative: It is always used immediately prior to an array access,
	* which throws an ArrayIndexOutOfBoundsException if index is negative.
	*/
	private void rangeCheck(int index) {
	if (index >= size)
	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
	}

	/**
	* 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;
	}

	/**
	* 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) {
	Objects.requireNonNull(c);
	return batchRemove(c, false);
	}

	/**
	* 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) {
	Objects.requireNonNull(c);
	return batchRemove(c, true);
	}

	private boolean batchRemove(Collection<?> c, boolean complement) {
	final Object[] elementData = this.elementData;
	int r = 0, w = 0;
	boolean modified = false;
	try {
	for (; r < size; r++)
	if (c.contains(elementData[r]) == complement)
	elementData[w++] = elementData[r];
	} finally {
	// Preserve behavioral compatibility with AbstractCollection,
	// even if c.contains() throws.
	if (r != size) {
	System.arraycopy(elementData, r,
	elementData, w,
	size - r);
	w += size - r;
	}
	if (w != size) {
	// clear to let GC do its work
	for (int i = w; i < size; i++)
	elementData[i] = null;
	modCount += size - w;
	size = w;
	modified = true;
	}
	}
	return modified;
	}

	/**
	* Save the state of the <tt>ArrayList</tt> instance to a stream (that
	* is, serialize it).
	*
	* @serialData The length of the array backing the <tt>ArrayList</tt>
	* instance is emitted (int), followed by all of its elements
	* (each an <tt>Object</tt>) in the proper order.
	*/
	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 behavioural 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();
	}
	}

	/**
	* Reconstitute the <tt>ArrayList</tt> instance from a stream (that is,
	* deserialize it).
	*/
	private void readObject(java.io.ObjectInputStream s)
	throws java.io.IOException, ClassNotFoundException {
	elementData = EMPTY_ELEMENTDATA;

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

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

	if (size > 0) {
	// be like clone(), allocate array based upon size not capacity
	int capacity = calculateCapacity(elementData, size);
	SharedSecrets.getJavaOISAccess().checkArray(s, Object[].class, capacity);
	ensureCapacityInternal(size);

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

	/**
	* 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) {
	if (index < 0 \|\| index > size)
	throw new IndexOutOfBoundsException("Index: "+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;

	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
	@SuppressWarnings("unchecked")
	public void forEachRemaining(Consumer<? super E> consumer) {
	Objects.requireNonNull(consumer);
	final int size = ArrayList.this.size;
	int i = cursor;
	if (i >= size) {
	return;
	}
	final Object[] elementData = ArrayList.this.elementData;
	if (i >= elementData.length) {
	throw new ConcurrentModificationException();
	}
	while (i != size && modCount == expectedModCount) {
	consumer.accept((E) elementData[i++]);
	}
	// update once at end of iteration 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, 0, fromIndex, toIndex);
	}

	static void subListRangeCheck(int fromIndex, int toIndex, int size) {
	if (fromIndex < 0)
	throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
	if (toIndex > size)
	throw new IndexOutOfBoundsException("toIndex = " + toIndex);
	if (fromIndex > toIndex)
	throw new IllegalArgumentException("fromIndex(" + fromIndex +
	") > toIndex(" + toIndex + ")");
	}

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

	SubList(AbstractList<E> parent,
	int offset, int fromIndex, int toIndex) {
	this.parent = parent;
	this.parentOffset = fromIndex;
	this.offset = offset + fromIndex;
	this.size = toIndex - fromIndex;
	this.modCount = ArrayList.this.modCount;
	}

	public E set(int index, E e) {
	rangeCheck(index);
	checkForComodification();
	E oldValue = ArrayList.this.elementData(offset + index);
	ArrayList.this.elementData[offset + index] = e;
	return oldValue;
	}

	public E get(int index) {
	rangeCheck(index);
	checkForComodification();
	return ArrayList.this.elementData(offset + index);
	}

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

	public void add(int index, E e) {
	rangeCheckForAdd(index);
	checkForComodification();
	parent.add(parentOffset + index, e);
	this.modCount = parent.modCount;
	this.size++;
	}

	public E remove(int index) {
	rangeCheck(index);
	checkForComodification();
	E result = parent.remove(parentOffset + index);
	this.modCount = parent.modCount;
	this.size--;
	return result;
	}

	protected void removeRange(int fromIndex, int toIndex) {
	checkForComodification();
	parent.removeRange(parentOffset + fromIndex,
	parentOffset + toIndex);
	this.modCount = parent.modCount;
	this.size -= toIndex - fromIndex;
	}

	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();
	parent.addAll(parentOffset + index, c);
	this.modCount = parent.modCount;
	this.size += cSize;
	return true;
	}

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

	public ListIterator<E> listIterator(final int index) {
	checkForComodification();
	rangeCheckForAdd(index);
	final int offset = this.offset;

	return new ListIterator<E>() {
	int cursor = index;
	int lastRet = -1;
	int expectedModCount = ArrayList.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 = ArrayList.this.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 = ArrayList.this.elementData;
	if (offset + i >= elementData.length)
	throw new ConcurrentModificationException();
	cursor = i;
	return (E) elementData[offset + (lastRet = i)];
	}

	@SuppressWarnings("unchecked")
	public void forEachRemaining(Consumer<? super E> consumer) {
	Objects.requireNonNull(consumer);
	final int size = SubList.this.size;
	int i = cursor;
	if (i >= size) {
	return;
	}
	final Object[] elementData = ArrayList.this.elementData;
	if (offset + i >= elementData.length) {
	throw new ConcurrentModificationException();
	}
	while (i != size && modCount == expectedModCount) {
	consumer.accept((E) elementData[offset + (i++)]);
	}
	// update once at end of iteration to reduce heap write traffic
	lastRet = cursor = i;
	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 = ArrayList.this.modCount;
	} catch (IndexOutOfBoundsException ex) {
	throw new ConcurrentModificationException();
	}
	}

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

	try {
	ArrayList.this.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 = ArrayList.this.modCount;
	} catch (IndexOutOfBoundsException ex) {
	throw new ConcurrentModificationException();
	}
	}

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

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

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

	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 (ArrayList.this.modCount != this.modCount)
	throw new ConcurrentModificationException();
	}

	public Spliterator<E> spliterator() {
	checkForComodification();
	return new ArrayListSpliterator<E>(ArrayList.this, offset,
	offset + this.size, this.modCount);
	}
	}

	@Override
	public void forEach(Consumer<? super E> action) {
	Objects.requireNonNull(action);
	final int expectedModCount = modCount;
	@SuppressWarnings("unchecked")
	final E[] elementData = (E[]) this.elementData;
	final int size = this.size;
	for (int i=0; modCount == expectedModCount && i < size; i++) {
	action.accept(elementData[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<>(this, 0, -1, 0);
	}

	/** Index-based split-by-two, lazily initialized Spliterator */
	static final class ArrayListSpliterator<E> 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 final ArrayList<E> list;
	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

	/** Create new spliterator covering the given range */
	ArrayListSpliterator(ArrayList<E> list, int origin, int fence,
	int expectedModCount) {
	this.list = list; // OK if null unless traversed
	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)
	ArrayList<E> lst;
	if ((hi = fence) < 0) {
	if ((lst = list) == null)
	hi = fence = 0;
	else {
	expectedModCount = lst.modCount;
	hi = fence = lst.size;
	}
	}
	return hi;
	}

	public ArrayListSpliterator<E> trySplit() {
	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
	return (lo >= mid) ? null : // divide range in half unless too small
	new ArrayListSpliterator<E>(list, 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)list.elementData[i];
	action.accept(e);
	if (list.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
	ArrayList<E> lst; Object[] a;
	if (action == null)
	throw new NullPointerException();
	if ((lst = list) != null && (a = lst.elementData) != null) {
	if ((hi = fence) < 0) {
	mc = lst.modCount;
	hi = lst.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 (long) (getFence() - index);
	}

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

	@Override
	public boolean removeIf(Predicate<? super E> filter) {
	Objects.requireNonNull(filter);
	// figure out which elements are to be removed
	// any exception thrown from the filter predicate at this stage
	// will leave the collection unmodified
	int removeCount = 0;
	final BitSet removeSet = new BitSet(size);
	final int expectedModCount = modCount;
	final int size = this.size;
	for (int i=0; modCount == expectedModCount && i < size; i++) {
	@SuppressWarnings("unchecked")
	final E element = (E) elementData[i];
	if (filter.test(element)) {
	removeSet.set(i);
	removeCount++;
	}
	}
	if (modCount != expectedModCount) {
	throw new ConcurrentModificationException();
	}

	// shift surviving elements left over the spaces left by removed elements
	final boolean anyToRemove = removeCount > 0;
	if (anyToRemove) {
	final int newSize = size - removeCount;
	for (int i=0, j=0; (i < size) && (j < newSize); i++, j++) {
	i = removeSet.nextClearBit(i);
	elementData[j] = elementData[i];
	}
	for (int k=newSize; k < size; k++) {
	elementData[k] = null; // Let gc do its work
	}
	this.size = newSize;
	if (modCount != expectedModCount) {
	throw new ConcurrentModificationException();
	}
	modCount++;
	}

	return anyToRemove;
	}

	@Override
	@SuppressWarnings("unchecked")
	public void replaceAll(UnaryOperator<E> operator) {
	Objects.requireNonNull(operator);
	final int expectedModCount = modCount;
	final int size = this.size;
	for (int i=0; modCount == expectedModCount && i < size; i++) {
	elementData[i] = operator.apply((E) elementData[i]);
	}
	if (modCount != expectedModCount) {
	throw new ConcurrentModificationException();
	}
	modCount++;
	}

	@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++;
	}
	}

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