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	/*
	* Copyright (c) 1994, 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.io.IOException;
	import java.io.ObjectInputStream;
	import java.io.StreamCorruptedException;
	import java.util.function.Consumer;
	import java.util.function.Predicate;
	import java.util.function.UnaryOperator;

	/**
	* The {@code Vector} class implements a growable array of
	* objects. Like an array, it contains components that can be
	* accessed using an integer index. However, the size of a
	* {@code Vector} can grow or shrink as needed to accommodate
	* adding and removing items after the {@code Vector} has been created.
	*
	* <p>Each vector tries to optimize storage management by maintaining a
	* {@code capacity} and a {@code capacityIncrement}. The
	* {@code capacity} is always at least as large as the vector
	* size; it is usually larger because as components are added to the
	* vector, the vector's storage increases in chunks the size of
	* {@code capacityIncrement}. An application can increase the
	* capacity of a vector before inserting a large number of
	* components; this reduces the amount of incremental reallocation.
	*
	* <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 vector 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. The {@link Enumeration Enumerations} returned by
	* the {@link #elements() elements} method are <em>not</em> fail-fast.
	*
	* <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>As of the Java 2 platform v1.2, this class was retrofitted to
	* implement the {@link List} interface, making it a member of the
	* <a href="{@docRoot}/../technotes/guides/collections/index.html">
	* Java Collections Framework</a>. Unlike the new collection
	* implementations, {@code Vector} is synchronized. If a thread-safe
	* implementation is not needed, it is recommended to use {@link
	* ArrayList} in place of {@code Vector}.
	*
	* @author Lee Boynton
	* @author Jonathan Payne
	* @see Collection
	* @see LinkedList
	* @since JDK1.0
	*/
	public class Vector<E>
	extends AbstractList<E>
	implements List<E>, RandomAccess, Cloneable, java.io.Serializable
	{
	/**
	* The array buffer into which the components of the vector are
	* stored. The capacity of the vector is the length of this array buffer,
	* and is at least large enough to contain all the vector's elements.
	*
	* <p>Any array elements following the last element in the Vector are null.
	*
	* @serial
	*/
	protected Object[] elementData;

	/**
	* The number of valid components in this {@code Vector} object.
	* Components {@code elementData[0]} through
	* {@code elementData[elementCount-1]} are the actual items.
	*
	* @serial
	*/
	protected int elementCount;

	/**
	* The amount by which the capacity of the vector is automatically
	* incremented when its size becomes greater than its capacity. If
	* the capacity increment is less than or equal to zero, the capacity
	* of the vector is doubled each time it needs to grow.
	*
	* @serial
	*/
	protected int capacityIncrement;

	/** use serialVersionUID from JDK 1.0.2 for interoperability */
	private static final long serialVersionUID = -2767605614048989439L;

	/**
	* Constructs an empty vector with the specified initial capacity and
	* capacity increment.
	*
	* @param initialCapacity the initial capacity of the vector
	* @param capacityIncrement the amount by which the capacity is
	* increased when the vector overflows
	* @throws IllegalArgumentException if the specified initial capacity
	* is negative
	*/
	public Vector(int initialCapacity, int capacityIncrement) {
	super();
	if (initialCapacity < 0)
	throw new IllegalArgumentException("Illegal Capacity: "+
	initialCapacity);
	this.elementData = new Object[initialCapacity];
	this.capacityIncrement = capacityIncrement;
	}

	/**
	* Constructs an empty vector with the specified initial capacity and
	* with its capacity increment equal to zero.
	*
	* @param initialCapacity the initial capacity of the vector
	* @throws IllegalArgumentException if the specified initial capacity
	* is negative
	*/
	public Vector(int initialCapacity) {
	this(initialCapacity, 0);
	}

	/**
	* Constructs an empty vector so that its internal data array
	* has size {@code 10} and its standard capacity increment is
	* zero.
	*/
	public Vector() {
	this(10);
	}

	/**
	* Constructs a vector 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
	* vector
	* @throws NullPointerException if the specified collection is null
	* @since 1.2
	*/
	public Vector(Collection<? extends E> c) {
	Object[] a = c.toArray();
	elementCount = a.length;
	if (c.getClass() == ArrayList.class) {
	elementData = a;
	} else {
	elementData = Arrays.copyOf(a, elementCount, Object[].class);
	}
	}

	/**
	* Copies the components of this vector into the specified array.
	* The item at index {@code k} in this vector is copied into
	* component {@code k} of {@code anArray}.
	*
	* @param anArray the array into which the components get copied
	* @throws NullPointerException if the given array is null
	* @throws IndexOutOfBoundsException if the specified array is not
	* large enough to hold all the components of this vector
	* @throws ArrayStoreException if a component of this vector is not of
	* a runtime type that can be stored in the specified array
	* @see #toArray(Object[])
	*/
	public synchronized void copyInto(Object[] anArray) {
	System.arraycopy(elementData, 0, anArray, 0, elementCount);
	}

	/**
	* Trims the capacity of this vector to be the vector's current
	* size. If the capacity of this vector is larger than its current
	* size, then the capacity is changed to equal the size by replacing
	* its internal data array, kept in the field {@code elementData},
	* with a smaller one. An application can use this operation to
	* minimize the storage of a vector.
	*/
	public synchronized void trimToSize() {
	modCount++;
	int oldCapacity = elementData.length;
	if (elementCount < oldCapacity) {
	elementData = Arrays.copyOf(elementData, elementCount);
	}
	}

	/**
	* Increases the capacity of this vector, if necessary, to ensure
	* that it can hold at least the number of components specified by
	* the minimum capacity argument.
	*
	* <p>If the current capacity of this vector is less than
	* {@code minCapacity}, then its capacity is increased by replacing its
	* internal data array, kept in the field {@code elementData}, with a
	* larger one. The size of the new data array will be the old size plus
	* {@code capacityIncrement}, unless the value of
	* {@code capacityIncrement} is less than or equal to zero, in which case
	* the new capacity will be twice the old capacity; but if this new size
	* is still smaller than {@code minCapacity}, then the new capacity will
	* be {@code minCapacity}.
	*
	* @param minCapacity the desired minimum capacity
	*/
	public synchronized void ensureCapacity(int minCapacity) {
	if (minCapacity > 0) {
	modCount++;
	ensureCapacityHelper(minCapacity);
	}
	}

	/**
	* This implements the unsynchronized semantics of ensureCapacity.
	* Synchronized methods in this class can internally call this
	* method for ensuring capacity without incurring the cost of an
	* extra synchronization.
	*
	* @see #ensureCapacity(int)
	*/
	private void ensureCapacityHelper(int minCapacity) {
	// 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;

	private void grow(int minCapacity) {
	// overflow-conscious code
	int oldCapacity = elementData.length;
	int newCapacity = oldCapacity + ((capacityIncrement > 0) ?
	capacityIncrement : oldCapacity);
	if (newCapacity - minCapacity < 0)
	newCapacity = minCapacity;
	if (newCapacity - MAX_ARRAY_SIZE > 0)
	newCapacity = hugeCapacity(minCapacity);
	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;
	}

	/**
	* Sets the size of this vector. If the new size is greater than the
	* current size, new {@code null} items are added to the end of
	* the vector. If the new size is less than the current size, all
	* components at index {@code newSize} and greater are discarded.
	*
	* @param newSize the new size of this vector
	* @throws ArrayIndexOutOfBoundsException if the new size is negative
	*/
	public synchronized void setSize(int newSize) {
	modCount++;
	if (newSize > elementCount) {
	ensureCapacityHelper(newSize);
	} else {
	for (int i = newSize ; i < elementCount ; i++) {
	elementData[i] = null;
	}
	}
	elementCount = newSize;
	}

	/**
	* Returns the current capacity of this vector.
	*
	* @return the current capacity (the length of its internal
	* data array, kept in the field {@code elementData}
	* of this vector)
	*/
	public synchronized int capacity() {
	return elementData.length;
	}

	/**
	* Returns the number of components in this vector.
	*
	* @return the number of components in this vector
	*/
	public synchronized int size() {
	return elementCount;
	}

	/**
	* Tests if this vector has no components.
	*
	* @return {@code true} if and only if this vector has
	* no components, that is, its size is zero;
	* {@code false} otherwise.
	*/
	public synchronized boolean isEmpty() {
	return elementCount == 0;
	}

	/**
	* Returns an enumeration of the components of this vector. The
	* returned {@code Enumeration} object will generate all items in
	* this vector. The first item generated is the item at index {@code 0},
	* then the item at index {@code 1}, and so on.
	*
	* @return an enumeration of the components of this vector
	* @see Iterator
	*/
	public Enumeration<E> elements() {
	return new Enumeration<E>() {
	int count = 0;

	public boolean hasMoreElements() {
	return count < elementCount;
	}

	public E nextElement() {
	synchronized (Vector.this) {
	if (count < elementCount) {
	return elementData(count++);
	}
	}
	throw new NoSuchElementException("Vector Enumeration");
	}
	};
	}

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

	/**
	* Returns the index of the first occurrence of the specified element
	* in this vector, or -1 if this vector does not contain the element.
	* More formally, returns the lowest index {@code i} such that
	* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
	* or -1 if there is no such index.
	*
	* @param o element to search for
	* @return the index of the first occurrence of the specified element in
	* this vector, or -1 if this vector does not contain the element
	*/
	public int indexOf(Object o) {
	return indexOf(o, 0);
	}

	/**
	* Returns the index of the first occurrence of the specified element in
	* this vector, searching forwards from {@code index}, or returns -1 if
	* the element is not found.
	* More formally, returns the lowest index {@code i} such that
	* <tt>(i >= index && (o==null ? get(i)==null : o.equals(get(i))))</tt>,
	* or -1 if there is no such index.
	*
	* @param o element to search for
	* @param index index to start searching from
	* @return the index of the first occurrence of the element in
	* this vector at position {@code index} or later in the vector;
	* {@code -1} if the element is not found.
	* @throws IndexOutOfBoundsException if the specified index is negative
	* @see Object#equals(Object)
	*/
	public synchronized int indexOf(Object o, int index) {
	if (o == null) {
	for (int i = index ; i < elementCount ; i++)
	if (elementData[i]==null)
	return i;
	} else {
	for (int i = index ; i < elementCount ; i++)
	if (o.equals(elementData[i]))
	return i;
	}
	return -1;
	}

	/**
	* Returns the index of the last occurrence of the specified element
	* in this vector, or -1 if this vector does not contain the element.
	* More formally, returns the highest index {@code i} such that
	* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
	* or -1 if there is no such index.
	*
	* @param o element to search for
	* @return the index of the last occurrence of the specified element in
	* this vector, or -1 if this vector does not contain the element
	*/
	public synchronized int lastIndexOf(Object o) {
	return lastIndexOf(o, elementCount-1);
	}

	/**
	* Returns the index of the last occurrence of the specified element in
	* this vector, searching backwards from {@code index}, or returns -1 if
	* the element is not found.
	* More formally, returns the highest index {@code i} such that
	* <tt>(i <= index && (o==null ? get(i)==null : o.equals(get(i))))</tt>,
	* or -1 if there is no such index.
	*
	* @param o element to search for
	* @param index index to start searching backwards from
	* @return the index of the last occurrence of the element at position
	* less than or equal to {@code index} in this vector;
	* -1 if the element is not found.
	* @throws IndexOutOfBoundsException if the specified index is greater
	* than or equal to the current size of this vector
	*/
	public synchronized int lastIndexOf(Object o, int index) {
	if (index >= elementCount)
	throw new IndexOutOfBoundsException(index + " >= "+ elementCount);

	if (o == null) {
	for (int i = index; i >= 0; i--)
	if (elementData[i]==null)
	return i;
	} else {
	for (int i = index; i >= 0; i--)
	if (o.equals(elementData[i]))
	return i;
	}
	return -1;
	}

	/**
	* Returns the component at the specified index.
	*
	* <p>This method is identical in functionality to the {@link #get(int)}
	* method (which is part of the {@link List} interface).
	*
	* @param index an index into this vector
	* @return the component at the specified index
	* @throws ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	*/
	public synchronized E elementAt(int index) {
	if (index >= elementCount) {
	throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount);
	}

	return elementData(index);
	}

	/**
	* Returns the first component (the item at index {@code 0}) of
	* this vector.
	*
	* @return the first component of this vector
	* @throws NoSuchElementException if this vector has no components
	*/
	public synchronized E firstElement() {
	if (elementCount == 0) {
	throw new NoSuchElementException();
	}
	return elementData(0);
	}

	/**
	* Returns the last component of the vector.
	*
	* @return the last component of the vector, i.e., the component at index
	* <code>size() - 1</code>.
	* @throws NoSuchElementException if this vector is empty
	*/
	public synchronized E lastElement() {
	if (elementCount == 0) {
	throw new NoSuchElementException();
	}
	return elementData(elementCount - 1);
	}

	/**
	* Sets the component at the specified {@code index} of this
	* vector to be the specified object. The previous component at that
	* position is discarded.
	*
	* <p>The index must be a value greater than or equal to {@code 0}
	* and less than the current size of the vector.
	*
	* <p>This method is identical in functionality to the
	* {@link #set(int, Object) set(int, E)}
	* method (which is part of the {@link List} interface). Note that the
	* {@code set} method reverses the order of the parameters, to more closely
	* match array usage. Note also that the {@code set} method returns the
	* old value that was stored at the specified position.
	*
	* @param obj what the component is to be set to
	* @param index the specified index
	* @throws ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	*/
	public synchronized void setElementAt(E obj, int index) {
	if (index >= elementCount) {
	throw new ArrayIndexOutOfBoundsException(index + " >= " +
	elementCount);
	}
	elementData[index] = obj;
	}

	/**
	* Deletes the component at the specified index. Each component in
	* this vector with an index greater or equal to the specified
	* {@code index} is shifted downward to have an index one
	* smaller than the value it had previously. The size of this vector
	* is decreased by {@code 1}.
	*
	* <p>The index must be a value greater than or equal to {@code 0}
	* and less than the current size of the vector.
	*
	* <p>This method is identical in functionality to the {@link #remove(int)}
	* method (which is part of the {@link List} interface). Note that the
	* {@code remove} method returns the old value that was stored at the
	* specified position.
	*
	* @param index the index of the object to remove
	* @throws ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	*/
	public synchronized void removeElementAt(int index) {
	modCount++;
	if (index >= elementCount) {
	throw new ArrayIndexOutOfBoundsException(index + " >= " +
	elementCount);
	}
	else if (index < 0) {
	throw new ArrayIndexOutOfBoundsException(index);
	}
	int j = elementCount - index - 1;
	if (j > 0) {
	System.arraycopy(elementData, index + 1, elementData, index, j);
	}
	elementCount--;
	elementData[elementCount] = null; /* to let gc do its work */
	}

	/**
	* Inserts the specified object as a component in this vector at the
	* specified {@code index}. Each component in this vector with
	* an index greater or equal to the specified {@code index} is
	* shifted upward to have an index one greater than the value it had
	* previously.
	*
	* <p>The index must be a value greater than or equal to {@code 0}
	* and less than or equal to the current size of the vector. (If the
	* index is equal to the current size of the vector, the new element
	* is appended to the Vector.)
	*
	* <p>This method is identical in functionality to the
	* {@link #add(int, Object) add(int, E)}
	* method (which is part of the {@link List} interface). Note that the
	* {@code add} method reverses the order of the parameters, to more closely
	* match array usage.
	*
	* @param obj the component to insert
	* @param index where to insert the new component
	* @throws ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index > size()})
	*/
	public synchronized void insertElementAt(E obj, int index) {
	modCount++;
	if (index > elementCount) {
	throw new ArrayIndexOutOfBoundsException(index
	+ " > " + elementCount);
	}
	ensureCapacityHelper(elementCount + 1);
	System.arraycopy(elementData, index, elementData, index + 1, elementCount - index);
	elementData[index] = obj;
	elementCount++;
	}

	/**
	* Adds the specified component to the end of this vector,
	* increasing its size by one. The capacity of this vector is
	* increased if its size becomes greater than its capacity.
	*
	* <p>This method is identical in functionality to the
	* {@link #add(Object) add(E)}
	* method (which is part of the {@link List} interface).
	*
	* @param obj the component to be added
	*/
	public synchronized void addElement(E obj) {
	modCount++;
	ensureCapacityHelper(elementCount + 1);
	elementData[elementCount++] = obj;
	}

	/**
	* Removes the first (lowest-indexed) occurrence of the argument
	* from this vector. If the object is found in this vector, each
	* component in the vector with an index greater or equal to the
	* object's index is shifted downward to have an index one smaller
	* than the value it had previously.
	*
	* <p>This method is identical in functionality to the
	* {@link #remove(Object)} method (which is part of the
	* {@link List} interface).
	*
	* @param obj the component to be removed
	* @return {@code true} if the argument was a component of this
	* vector; {@code false} otherwise.
	*/
	public synchronized boolean removeElement(Object obj) {
	modCount++;
	int i = indexOf(obj);
	if (i >= 0) {
	removeElementAt(i);
	return true;
	}
	return false;
	}

	/**
	* Removes all components from this vector and sets its size to zero.
	*
	* <p>This method is identical in functionality to the {@link #clear}
	* method (which is part of the {@link List} interface).
	*/
	public synchronized void removeAllElements() {
	modCount++;
	// Let gc do its work
	for (int i = 0; i < elementCount; i++)
	elementData[i] = null;

	elementCount = 0;
	}

	/**
	* Returns a clone of this vector. The copy will contain a
	* reference to a clone of the internal data array, not a reference
	* to the original internal data array of this {@code Vector} object.
	*
	* @return a clone of this vector
	*/
	public synchronized Object clone() {
	try {
	@SuppressWarnings("unchecked")
	Vector<E> v = (Vector<E>) super.clone();
	v.elementData = Arrays.copyOf(elementData, elementCount);
	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 Vector
	* in the correct order.
	*
	* @since 1.2
	*/
	public synchronized Object[] toArray() {
	return Arrays.copyOf(elementData, elementCount);
	}

	/**
	* Returns an array containing all of the elements in this Vector in the
	* correct order; the runtime type of the returned array is that of the
	* specified array. If the Vector 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 Vector.
	*
	* <p>If the Vector fits in the specified array with room to spare
	* (i.e., the array has more elements than the Vector),
	* the element in the array immediately following the end of the
	* Vector is set to null. (This is useful in determining the length
	* of the Vector <em>only</em> if the caller knows that the Vector
	* does not contain any null elements.)
	*
	* @param a the array into which the elements of the Vector 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 Vector
	* @throws ArrayStoreException if the runtime type of a is not a supertype
	* of the runtime type of every element in this Vector
	* @throws NullPointerException if the given array is null
	* @since 1.2
	*/
	@SuppressWarnings("unchecked")
	public synchronized <T> T[] toArray(T[] a) {
	if (a.length < elementCount)
	return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass());

	System.arraycopy(elementData, 0, a, 0, elementCount);

	if (a.length > elementCount)
	a[elementCount] = 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 Vector.
	*
	* @param index index of the element to return
	* @return object at the specified index
	* @throws ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	* @since 1.2
	*/
	public synchronized E get(int index) {
	if (index >= elementCount)
	throw new ArrayIndexOutOfBoundsException(index);

	return elementData(index);
	}

	/**
	* Replaces the element at the specified position in this Vector 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 ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	* @since 1.2
	*/
	public synchronized E set(int index, E element) {
	if (index >= elementCount)
	throw new ArrayIndexOutOfBoundsException(index);

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

	/**
	* Appends the specified element to the end of this Vector.
	*
	* @param e element to be appended to this Vector
	* @return {@code true} (as specified by {@link Collection#add})
	* @since 1.2
	*/
	public synchronized boolean add(E e) {
	modCount++;
	ensureCapacityHelper(elementCount + 1);
	elementData[elementCount++] = e;
	return true;
	}

	/**
	* Removes the first occurrence of the specified element in this Vector
	* If the Vector does not contain the element, it is unchanged. More
	* formally, removes the element with the lowest index i such that
	* {@code (o==null ? get(i)==null : o.equals(get(i)))} (if such
	* an element exists).
	*
	* @param o element to be removed from this Vector, if present
	* @return true if the Vector contained the specified element
	* @since 1.2
	*/
	public boolean remove(Object o) {
	return removeElement(o);
	}

	/**
	* Inserts the specified element at the specified position in this Vector.
	* 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 ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index > size()})
	* @since 1.2
	*/
	public void add(int index, E element) {
	insertElementAt(element, index);
	}

	/**
	* Removes the element at the specified position in this Vector.
	* Shifts any subsequent elements to the left (subtracts one from their
	* indices). Returns the element that was removed from the Vector.
	*
	* @throws ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	* @param index the index of the element to be removed
	* @return element that was removed
	* @since 1.2
	*/
	public synchronized E remove(int index) {
	modCount++;
	if (index >= elementCount)
	throw new ArrayIndexOutOfBoundsException(index);
	E oldValue = elementData(index);

	int numMoved = elementCount - index - 1;
	if (numMoved > 0)
	System.arraycopy(elementData, index+1, elementData, index,
	numMoved);
	elementData[--elementCount] = null; // Let gc do its work

	return oldValue;
	}

	/**
	* Removes all of the elements from this Vector. The Vector will
	* be empty after this call returns (unless it throws an exception).
	*
	* @since 1.2
	*/
	public void clear() {
	removeAllElements();
	}

	// Bulk Operations

	/**
	* Returns true if this Vector contains all of the elements in the
	* specified Collection.
	*
	* @param c a collection whose elements will be tested for containment
	* in this Vector
	* @return true if this Vector contains all of the elements in the
	* specified collection
	* @throws NullPointerException if the specified collection is null
	*/
	public synchronized boolean containsAll(Collection<?> c) {
	return super.containsAll(c);
	}

	/**
	* Appends all of the elements in the specified Collection to the end of
	* this Vector, 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 Vector, and this Vector is nonempty.)
	*
	* @param c elements to be inserted into this Vector
	* @return {@code true} if this Vector changed as a result of the call
	* @throws NullPointerException if the specified collection is null
	* @since 1.2
	*/
	public synchronized boolean addAll(Collection<? extends E> c) {
	modCount++;
	Object[] a = c.toArray();
	int numNew = a.length;
	ensureCapacityHelper(elementCount + numNew);
	System.arraycopy(a, 0, elementData, elementCount, numNew);
	elementCount += numNew;
	return numNew != 0;
	}

	/**
	* Removes from this Vector all of its elements that are contained in the
	* specified Collection.
	*
	* @param c a collection of elements to be removed from the Vector
	* @return true if this Vector changed as a result of the call
	* @throws ClassCastException if the types of one or more elements
	* in this vector are incompatible with the specified
	* collection
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if this vector contains one or more null
	* elements and the specified collection does not support null
	* elements
	* (<a href="Collection.html#optional-restrictions">optional</a>),
	* or if the specified collection is null
	* @since 1.2
	*/
	public synchronized boolean removeAll(Collection<?> c) {
	return super.removeAll(c);
	}

	/**
	* Retains only the elements in this Vector that are contained in the
	* specified Collection. In other words, removes from this Vector all
	* of its elements that are not contained in the specified Collection.
	*
	* @param c a collection of elements to be retained in this Vector
	* (all other elements are removed)
	* @return true if this Vector changed as a result of the call
	* @throws ClassCastException if the types of one or more elements
	* in this vector are incompatible with the specified
	* collection
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if this vector contains one or more null
	* elements and the specified collection does not support null
	* elements
	* (<a href="Collection.html#optional-restrictions">optional</a>),
	* or if the specified collection is null
	* @since 1.2
	*/
	public synchronized boolean retainAll(Collection<?> c) {
	return super.retainAll(c);
	}

	/**
	* Inserts all of the elements in the specified Collection into this
	* Vector 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 Vector
	* 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 elements to be inserted into this Vector
	* @return {@code true} if this Vector changed as a result of the call
	* @throws ArrayIndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index > size()})
	* @throws NullPointerException if the specified collection is null
	* @since 1.2
	*/
	public synchronized boolean addAll(int index, Collection<? extends E> c) {
	modCount++;
	if (index < 0 \|\| index > elementCount)
	throw new ArrayIndexOutOfBoundsException(index);

	Object[] a = c.toArray();
	int numNew = a.length;
	ensureCapacityHelper(elementCount + numNew);

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

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

	/**
	* Compares the specified Object with this Vector for equality. Returns
	* true if and only if the specified Object is also a List, both Lists
	* have the same size, and all corresponding pairs of elements in the two
	* Lists are <em>equal</em>. (Two elements {@code e1} and
	* {@code e2} are <em>equal</em> if {@code (e1==null ? e2==null :
	* e1.equals(e2))}.) In other words, two Lists are defined to be
	* equal if they contain the same elements in the same order.
	*
	* @param o the Object to be compared for equality with this Vector
	* @return true if the specified Object is equal to this Vector
	*/
	public synchronized boolean equals(Object o) {
	return super.equals(o);
	}

	/**
	* Returns the hash code value for this Vector.
	*/
	public synchronized int hashCode() {
	return super.hashCode();
	}

	/**
	* Returns a string representation of this Vector, containing
	* the String representation of each element.
	*/
	public synchronized String toString() {
	return super.toString();
	}

	/**
	* Returns a view of the portion of this List between fromIndex,
	* inclusive, and toIndex, exclusive. (If fromIndex and toIndex are
	* equal, the returned List is empty.) The returned List is backed by this
	* List, so changes in the returned List are reflected in this List, and
	* vice-versa. The returned List supports all of the optional List
	* operations supported by this List.
	*
	* <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 operating on 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 indexOf and lastIndexOf,
	* and all of the algorithms in the 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 the List, or otherwise perturb it in such
	* a fashion that iterations in progress may yield incorrect results.)
	*
	* @param fromIndex low endpoint (inclusive) of the subList
	* @param toIndex high endpoint (exclusive) of the subList
	* @return a view of the specified range within this List
	* @throws IndexOutOfBoundsException if an endpoint index value is out of range
	* {@code (fromIndex < 0 \|\| toIndex > size)}
	* @throws IllegalArgumentException if the endpoint indices are out of order
	* {@code (fromIndex > toIndex)}
	*/
	public synchronized List<E> subList(int fromIndex, int toIndex) {
	return Collections.synchronizedList(super.subList(fromIndex, toIndex),
	this);
	}

	/**
	* 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.)
	*/
	protected synchronized void removeRange(int fromIndex, int toIndex) {
	modCount++;
	int numMoved = elementCount - toIndex;
	System.arraycopy(elementData, toIndex, elementData, fromIndex,
	numMoved);

	// Let gc do its work
	int newElementCount = elementCount - (toIndex-fromIndex);
	while (elementCount != newElementCount)
	elementData[--elementCount] = null;
	}

	/**
	* Loads a {@code Vector} instance from a stream
	* (that is, deserializes it).
	* This method performs checks to ensure the consistency
	* of the fields.
	*
	* @param in the stream
	* @throws java.io.IOException if an I/O error occurs
	* @throws ClassNotFoundException if the stream contains data
	* of a non-existing class
	*/
	private void readObject(ObjectInputStream in)
	throws IOException, ClassNotFoundException {
	ObjectInputStream.GetField gfields = in.readFields();
	int count = gfields.get("elementCount", 0);
	Object[] data = (Object[])gfields.get("elementData", null);
	if (count < 0 \|\| data == null \|\| count > data.length) {
	throw new StreamCorruptedException("Inconsistent vector internals");
	}
	elementCount = count;
	elementData = data.clone();
	}

	/**
	* Save the state of the {@code Vector} instance to a stream (that
	* is, serialize it).
	* This method performs synchronization to ensure the consistency
	* of the serialized data.
	*/
	private void writeObject(java.io.ObjectOutputStream s)
	throws java.io.IOException {
	final java.io.ObjectOutputStream.PutField fields = s.putFields();
	final Object[] data;
	synchronized (this) {
	fields.put("capacityIncrement", capacityIncrement);
	fields.put("elementCount", elementCount);
	data = elementData.clone();
	}
	fields.put("elementData", data);
	s.writeFields();
	}

	/**
	* 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 synchronized ListIterator<E> listIterator(int index) {
	if (index < 0 \|\| index > elementCount)
	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 synchronized 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 synchronized 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;

	public boolean hasNext() {
	// Racy but within spec, since modifications are checked
	// within or after synchronization in next/previous
	return cursor != elementCount;
	}

	public E next() {
	synchronized (Vector.this) {
	checkForComodification();
	int i = cursor;
	if (i >= elementCount)
	throw new NoSuchElementException();
	cursor = i + 1;
	return elementData(lastRet = i);
	}
	}

	public void remove() {
	if (lastRet == -1)
	throw new IllegalStateException();
	synchronized (Vector.this) {
	checkForComodification();
	Vector.this.remove(lastRet);
	expectedModCount = modCount;
	}
	cursor = lastRet;
	lastRet = -1;
	}

	@Override
	public void forEachRemaining(Consumer<? super E> action) {
	Objects.requireNonNull(action);
	synchronized (Vector.this) {
	final int size = elementCount;
	int i = cursor;
	if (i >= size) {
	return;
	}
	@SuppressWarnings("unchecked")
	final E[] elementData = (E[]) Vector.this.elementData;
	if (i >= elementData.length) {
	throw new ConcurrentModificationException();
	}
	while (i != size && modCount == expectedModCount) {
	action.accept(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
	*/
	final 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;
	}

	public E previous() {
	synchronized (Vector.this) {
	checkForComodification();
	int i = cursor - 1;
	if (i < 0)
	throw new NoSuchElementException();
	cursor = i;
	return elementData(lastRet = i);
	}
	}

	public void set(E e) {
	if (lastRet == -1)
	throw new IllegalStateException();
	synchronized (Vector.this) {
	checkForComodification();
	Vector.this.set(lastRet, e);
	}
	}

	public void add(E e) {
	int i = cursor;
	synchronized (Vector.this) {
	checkForComodification();
	Vector.this.add(i, e);
	expectedModCount = modCount;
	}
	cursor = i + 1;
	lastRet = -1;
	}
	}

	@Override
	public synchronized void forEach(Consumer<? super E> action) {
	Objects.requireNonNull(action);
	final int expectedModCount = modCount;
	@SuppressWarnings("unchecked")
	final E[] elementData = (E[]) this.elementData;
	final int elementCount = this.elementCount;
	for (int i=0; modCount == expectedModCount && i < elementCount; i++) {
	action.accept(elementData[i]);
	}
	if (modCount != expectedModCount) {
	throw new ConcurrentModificationException();
	}
	}

	@Override
	@SuppressWarnings("unchecked")
	public synchronized 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 int size = elementCount;
	final BitSet removeSet = new BitSet(size);
	final int expectedModCount = modCount;
	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
	}
	elementCount = newSize;
	if (modCount != expectedModCount) {
	throw new ConcurrentModificationException();
	}
	modCount++;
	}

	return anyToRemove;
	}

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

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

	/**
	* 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 VectorSpliterator<>(this, null, 0, -1, 0);
	}

	/** Similar to ArrayList Spliterator */
	static final class VectorSpliterator<E> implements Spliterator<E> {
	private final Vector<E> list;
	private Object[] array;
	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 */
	VectorSpliterator(Vector<E> list, Object[] array, int origin, int fence,
	int expectedModCount) {
	this.list = list;
	this.array = array;
	this.index = origin;
	this.fence = fence;
	this.expectedModCount = expectedModCount;
	}

	private int getFence() { // initialize on first use
	int hi;
	if ((hi = fence) < 0) {
	synchronized(list) {
	array = list.elementData;
	expectedModCount = list.modCount;
	hi = fence = list.elementCount;
	}
	}
	return hi;
	}

	public Spliterator<E> trySplit() {
	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
	return (lo >= mid) ? null :
	new VectorSpliterator<E>(list, array, lo, index = mid,
	expectedModCount);
	}

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

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

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

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

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