Appends the specified element to the end of this list.

  Appends the specified element to the end of this list.
Returns: true (as specified by {@link Collection#add})
Parameters:
- e - element to be appended to this list

  Inserts the specified element at the specified position in this list.

  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).
Throws:
- IndexOutOfBoundsException - {@inheritDoc}

  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.

  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.
Returns: true if this list changed as a result of the call
Parameters:
- c - collection containing elements to be added to this list
Throws:
- NullPointerException - if the specified collection is null
See Also: CopyOnWriteArrayList.add(Object),

  Inserts all of the elements in the specified collection into this list, starting at the specified position.

  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 this list in the order that they are returned by the
specified collection's iterator.
Returns: true if this list changed as a result of the call
Parameters:
- index - index at which to insert the first element from the specified collection
- c - collection containing elements to be added to this list
Throws:
- IndexOutOfBoundsException - {@inheritDoc}
- NullPointerException - if the specified collection is null
See Also: CopyOnWriteArrayList.add(int,Object),

  Appends all of the elements in the specified collection that are not already contained in this list, to the end of this list, in the order that they are returned by the specified collection's iterator.

  Appends all of the elements in the specified collection that
are not already contained in this list, to the end of
this list, in the order that they are returned by the
specified collection's iterator.
Returns: the number of elements added
Parameters:
- c - collection containing elements to be added to this list
Throws:
- NullPointerException - if the specified collection is null
See Also: CopyOnWriteArrayList.addIfAbsent(Object),

  Append the element if not present.

  Append the element if not present.
Returns: true if the element was added
Parameters:
- e - element to be added to this list, if absent

  Removes all of the elements from this list.

  Removes all of the elements from this list.
The list will be empty after this call returns.

  Returns a shallow copy of this list.

  Returns a shallow copy of this list. (The elements themselves
are not copied.)
Returns: a clone of this list

  Returns true if this list contains the specified element.

  Returns true if this list contains the specified element.
More formally, returns true if and only if this list contains
at least one element e such that
(o==null ? e==null : o.equals(e)).
Returns: true if this list contains the specified element
Parameters:
- o - element whose presence in this list is to be tested

  Returns true if this list contains all of the elements of the specified collection.

  Returns true if this list contains all of the elements of the
specified collection.
Returns: true if this list contains all of the elements of the specified collection
Parameters:
- c - collection to be checked for containment in this list
Throws:
- NullPointerException - if the specified collection is null
See Also: CopyOnWriteArrayList.contains(Object),

  Compares the specified object with this list for equality.

  Compares the specified object with this list for equality.
Returns true if the specified object is the same object
as this object, or if it is also a List and the sequence
of elements returned by an iterator
over the specified list is the same as the sequence returned by
an iterator over this list. The two sequences are considered to
be the same if they have the same length and corresponding
elements at the same position in the sequence are equal.
Two elements e1 and e2 are considered
equal if (e1==null ? e2==null : e1.equals(e2)).
Returns: {@code true} if the specified object is equal to this list
Parameters:
- o - the object to be compared for equality with this list

  Returns the element at the specified position in this list.

  Returns the element at the specified position in this list.
Throws:
- IndexOutOfBoundsException - {@inheritDoc}

  Gets the array.

  Gets the array. Non-private so as to also be accessible
from CopyOnWriteArraySet class.

  Returns the hash code value for this list.

  Returns the hash code value for this list.

This implementation uses the definition in List.hashCode().
Returns: the hash code value for this list

  Returns the index of the first occurrence of the specified element in this list, searching forwards from index, or returns -1 if the element is not found.

  Returns the index of the first occurrence of the specified element in
this list, searching forwards from index, or returns -1 if
the element is not found.
More formally, returns the lowest index i such that
(i >= index && (e==null ? get(i)==null : e.equals(get(i)))),
or -1 if there is no such index.
Returns: the index of the first occurrence of the element in this list at position index or later in the list; -1 if the element is not found.
Parameters:
- e - element to search for
- index - index to start searching from
Throws:
- IndexOutOfBoundsException - if the specified index is negative

  Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.

  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 i such that
(o==null ? get(i)==null : o.equals(get(i))),
or -1 if there is no such index.

  Returns true if this list contains no elements.

  Returns true if this list contains no elements.
Returns: true if this list contains no elements

  Returns an iterator over the elements in this list in proper sequence.

  Returns an iterator over the elements in this list in proper sequence.

The returned iterator provides a snapshot of the state of the list when the iterator was constructed. No synchronization is needed while traversing the iterator. The iterator does NOT support the remove method.
Returns: an iterator over the elements in this list in proper sequence

  Returns the index of the last occurrence of the specified element in this list, searching backwards from index, or returns -1 if the element is not found.

  Returns the index of the last occurrence of the specified element in
this list, searching backwards from index, or returns -1 if
the element is not found.
More formally, returns the highest index i such that
(i <= index && (e==null ? get(i)==null : e.equals(get(i)))),
or -1 if there is no such index.
Returns: the index of the last occurrence of the element at position less than or equal to index in this list; -1 if the element is not found.
Parameters:
- e - element to search for
- index - index to start searching backwards from
Throws:
- IndexOutOfBoundsException - if the specified index is greater than or equal to the current size of this list

  Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.

  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 i such that
(o==null ? get(i)==null : o.equals(get(i))),
or -1 if there is no such index.

  Returns a list iterator over the elements in this list (in proper sequence).

  Returns a list iterator over the elements in this list (in proper sequence).

The returned iterator provides a snapshot of the state of the list when the iterator was constructed. No synchronization is needed while traversing the iterator. The iterator does NOT support the remove, set or add methods.

  Returns a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list.

  Returns a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list. The specified index indicates the first element that would be returned by an initial call to next. An initial call to previous would return the element with the specified index minus one.

The returned iterator provides a snapshot of the state of the list when the iterator was constructed. No synchronization is needed while traversing the iterator. The iterator does NOT support the remove, set or add methods.
Throws:
- IndexOutOfBoundsException - {@inheritDoc}

  Removes the element at the specified position in this list.

  Removes the element at the specified position in this list.
Shifts any subsequent elements to the left (subtracts one from their
indices). Returns the element that was removed from the list.
Throws:
- IndexOutOfBoundsException - {@inheritDoc}

  Removes the first occurrence of the specified element from this list, if it is present.

  Removes the first occurrence of the specified element from this list,
if it is present. If this list does not contain the element, it is
unchanged. More formally, removes the element with the lowest index
i such that
(o==null ? get(i)==null : o.equals(get(i)))
(if such an element exists). Returns true if this list
contained the specified element (or equivalently, if this list
changed as a result of the call).
Returns: true if this list contained the specified element
Parameters:
- o - element to be removed from this list, if present

  Removes from this list all of its elements that are contained in the specified collection.

  Removes from this list all of its elements that are contained in
the specified collection. This is a particularly expensive operation
in this class because of the need for an internal temporary array.
Returns: true if this list changed as a result of the call
Parameters:
- c - collection containing elements to be removed from this list
Throws:
- ClassCastException - if the class of an element of this list is incompatible with the specified collection (optional)
- NullPointerException - if this list contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null
See Also: CopyOnWriteArrayList.remove(Object),

  Retains only the elements in this list that are contained in the specified collection.

  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.
Returns: true if this list changed as a result of the call
Parameters:
- c - collection containing elements to be retained in this list
Throws:
- ClassCastException - if the class of an element of this list is incompatible with the specified collection (optional)
- NullPointerException - if this list contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null
See Also: CopyOnWriteArrayList.remove(Object),

  Replaces the element at the specified position in this list with the specified element.

  Replaces the element at the specified position in this list with the
specified element.
Throws:
- IndexOutOfBoundsException - {@inheritDoc}

Sets the array.

  Returns the number of elements in this list.

  Returns the number of elements in this list.
Returns: the number of elements in this list

  Returns a view of the portion of this list between fromIndex, inclusive, and toIndex, exclusive.

  Returns a view of the portion of this list between fromIndex, inclusive, and toIndex, exclusive. The returned list is backed by this list, so changes in the returned list are reflected in this list, and vice-versa. While mutative operations are supported, they are probably not very useful for CopyOnWriteArrayLists.

The semantics of the list returned by this method become undefined if the backing list (i.e., this list) is structurally modified 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.)
Returns: a view of the specified range within this list
Parameters:
- fromIndex - low endpoint (inclusive) of the subList
- toIndex - high endpoint (exclusive) of the subList
Throws:
- IndexOutOfBoundsException - {@inheritDoc}

  Returns an array containing all of the elements in this list in proper sequence (from first to last element).

  Returns an array containing all of the elements in this list in proper sequence (from first to last element).

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.

This method acts as bridge between array-based and collection-based APIs.
Returns: an array containing all the elements in this list

  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.

  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.

If this list fits in the specified array with room to spare (i.e., the array has more elements than this list), the element in the array immediately following the end of the list is set to null. (This is useful in determining the length of this list only if the caller knows that this list does not contain any null elements.)

Like the CopyOnWriteArrayList.toArray() method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs.

Suppose x is a list known to contain only strings. The following code can be used to dump the list into a newly allocated array of String:

     String[] y = x.toArray(new String[0]);

Note that toArray(new Object[0]) is identical in function to toArray().
Returns: an array containing all the elements in this list
Parameters:
- 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.
Throws:
- ArrayStoreException - if the runtime type of the specified array is not a supertype of the runtime type of every element in this list
- NullPointerException - if the specified array is null

  Returns a string representation of this list.

  Returns a string representation of this list. The string
representation consists of the string representations of the list's
elements in the order they are returned by its iterator, enclosed in
square brackets ("[]"). Adjacent elements are separated by
the characters ", " (comma and space). Elements are
converted to strings as by String.valueOf(Object).
Returns: a string representation of this list