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	/*
	* Copyright (c) 1997, 2018, 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.UnaryOperator;

	/**
	* An ordered collection (also known as a <i>sequence</i>). The user of this
	* interface has precise control over where in the list each element is
	* inserted. The user can access elements by their integer index (position in
	* the list), and search for elements in the list.<p>
	*
	* Unlike sets, lists typically allow duplicate elements. More formally,
	* lists typically allow pairs of elements {@code e1} and {@code e2}
	* such that {@code e1.equals(e2)}, and they typically allow multiple
	* null elements if they allow null elements at all. It is not inconceivable
	* that someone might wish to implement a list that prohibits duplicates, by
	* throwing runtime exceptions when the user attempts to insert them, but we
	* expect this usage to be rare.<p>
	*
	* The {@code List} interface places additional stipulations, beyond those
	* specified in the {@code Collection} interface, on the contracts of the
	* {@code iterator}, {@code add}, {@code remove}, {@code equals}, and
	* {@code hashCode} methods. Declarations for other inherited methods are
	* also included here for convenience.<p>
	*
	* The {@code List} interface provides four methods for positional (indexed)
	* access to list elements. Lists (like Java arrays) are zero based. Note
	* that these operations may execute in time proportional to the index value
	* for some implementations (the {@code LinkedList} class, for
	* example). Thus, iterating over the elements in a list is typically
	* preferable to indexing through it if the caller does not know the
	* implementation.<p>
	*
	* The {@code List} interface provides a special iterator, called a
	* {@code ListIterator}, that allows element insertion and replacement, and
	* bidirectional access in addition to the normal operations that the
	* {@code Iterator} interface provides. A method is provided to obtain a
	* list iterator that starts at a specified position in the list.<p>
	*
	* The {@code List} interface provides two methods to search for a specified
	* object. From a performance standpoint, these methods should be used with
	* caution. In many implementations they will perform costly linear
	* searches.<p>
	*
	* The {@code List} interface provides two methods to efficiently insert and
	* remove multiple elements at an arbitrary point in the list.<p>
	*
	* Note: While it is permissible for lists to contain themselves as elements,
	* extreme caution is advised: the {@code equals} and {@code hashCode}
	* methods are no longer well defined on such a list.
	*
	* <p>Some list implementations have restrictions on the elements that
	* they may contain. For example, some implementations prohibit null elements,
	* and some have restrictions on the types of their elements. Attempting to
	* add an ineligible element throws an unchecked exception, typically
	* {@code NullPointerException} or {@code ClassCastException}. Attempting
	* to query the presence of an ineligible element may throw an exception,
	* or it may simply return false; some implementations will exhibit the former
	* behavior and some will exhibit the latter. More generally, attempting an
	* operation on an ineligible element whose completion would not result in
	* the insertion of an ineligible element into the list may throw an
	* exception or it may succeed, at the option of the implementation.
	* Such exceptions are marked as "optional" in the specification for this
	* interface.
	*
	* <h2><a id="unmodifiable">Unmodifiable Lists</a></h2>
	* <p>The {@link List#of(Object...) List.of} and
	* {@link List#copyOf List.copyOf} static factory methods
	* provide a convenient way to create unmodifiable lists. The {@code List}
	* instances created by these methods have the following characteristics:
	*
	* <ul>
	* <li>They are <a href="Collection.html#unmodifiable"><i>unmodifiable</i></a>. Elements cannot
	* be added, removed, or replaced. Calling any mutator method on the List
	* will always cause {@code UnsupportedOperationException} to be thrown.
	* However, if the contained elements are themselves mutable,
	* this may cause the List's contents to appear to change.
	* <li>They disallow {@code null} elements. Attempts to create them with
	* {@code null} elements result in {@code NullPointerException}.
	* <li>They are serializable if all elements are serializable.
	* <li>The order of elements in the list is the same as the order of the
	* provided arguments, or of the elements in the provided array.
	* <li>They are <a href="../lang/doc-files/ValueBased.html">value-based</a>.
	* Callers should make no assumptions about the identity of the returned instances.
	* Factories are free to create new instances or reuse existing ones. Therefore,
	* identity-sensitive operations on these instances (reference equality ({@code ==}),
	* identity hash code, and synchronization) are unreliable and should be avoided.
	* <li>They are serialized as specified on the
	* <a href="{@docRoot}/serialized-form.html#java.util.CollSer">Serialized Form</a>
	* page.
	* </ul>
	*
	* <p>This interface is a member of the
	* <a href="{@docRoot}/java.base/java/util/package-summary.html#CollectionsFramework">
	* Java Collections Framework</a>.
	*
	* @param <E> the type of elements in this list
	*
	* @author Josh Bloch
	* @author Neal Gafter
	* @see Collection
	* @see Set
	* @see ArrayList
	* @see LinkedList
	* @see Vector
	* @see Arrays#asList(Object[])
	* @see Collections#nCopies(int, Object)
	* @see Collections#EMPTY_LIST
	* @see AbstractList
	* @see AbstractSequentialList
	* @since 1.2
	*/

	public interface List<E> extends Collection<E> {
	// Query Operations

	/**
	* Returns the number of elements in this list. If this list contains
	* more than {@code Integer.MAX_VALUE} elements, returns
	* {@code Integer.MAX_VALUE}.
	*
	* @return the number of elements in this list
	*/
	int size();

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

	/**
	* Returns {@code true} if this list contains the specified element.
	* More formally, returns {@code true} if and only if this list contains
	* at least one element {@code e} such that
	* {@code Objects.equals(o, e)}.
	*
	* @param o element whose presence in this list is to be tested
	* @return {@code true} if this list contains the specified element
	* @throws ClassCastException if the type of the specified element
	* is incompatible with this list
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if the specified element is null and this
	* list does not permit null elements
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	*/
	boolean contains(Object o);

	/**
	* Returns an iterator over the elements in this list in proper sequence.
	*
	* @return an iterator over the elements in this list in proper sequence
	*/
	Iterator<E> iterator();

	/**
	* 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 even if this list is backed by an 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
	* @see Arrays#asList(Object[])
	*/
	Object[] toArray();

	/**
	* 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 list is set to {@code null}.
	* (This is useful in determining the length of the list <i>only</i> if
	* the caller knows that the list does not contain any null elements.)
	*
	* <p>Like the {@link #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.
	*
	* <p>Suppose {@code 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 {@code String}:
	*
	* <pre>{@code
	* String[] y = x.toArray(new String[0]);
	* }</pre>
	*
	* Note that {@code toArray(new Object[0])} is identical in function to
	* {@code toArray()}.
	*
	* @param a the array into which the elements of this 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 this 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
	*/
	<T> T[] toArray(T[] a);


	// Modification Operations

	/**
	* Appends the specified element to the end of this list (optional
	* operation).
	*
	* <p>Lists that support this operation may place limitations on what
	* elements may be added to this list. In particular, some
	* lists will refuse to add null elements, and others will impose
	* restrictions on the type of elements that may be added. List
	* classes should clearly specify in their documentation any restrictions
	* on what elements may be added.
	*
	* @param e element to be appended to this list
	* @return {@code true} (as specified by {@link Collection#add})
	* @throws UnsupportedOperationException if the {@code add} operation
	* is not supported by this list
	* @throws ClassCastException if the class of the specified element
	* prevents it from being added to this list
	* @throws NullPointerException if the specified element is null and this
	* list does not permit null elements
	* @throws IllegalArgumentException if some property of this element
	* prevents it from being added to this list
	*/
	boolean add(E e);

	/**
	* Removes the first occurrence of the specified element from this list,
	* if it is present (optional operation). If this list does not contain
	* the element, it is unchanged. More formally, removes the element with
	* the lowest index {@code i} such that
	* {@code Objects.equals(o, get(i))}
	* (if such an element exists). Returns {@code true} if this list
	* contained the specified element (or equivalently, if this list changed
	* as a result of the call).
	*
	* @param o element to be removed from this list, if present
	* @return {@code true} if this list contained the specified element
	* @throws ClassCastException if the type of the specified element
	* is incompatible with this list
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if the specified element is null and this
	* list does not permit null elements
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws UnsupportedOperationException if the {@code remove} operation
	* is not supported by this list
	*/
	boolean remove(Object o);


	// Bulk Modification Operations

	/**
	* Returns {@code true} if this list contains all of the elements of the
	* specified collection.
	*
	* @param c collection to be checked for containment in this list
	* @return {@code true} if this list contains all of the elements of the
	* specified collection
	* @throws ClassCastException if the types of one or more elements
	* in the specified collection are incompatible with this
	* list
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if the specified collection contains one
	* or more null elements and this list does not permit null
	* elements
	* (<a href="Collection.html#optional-restrictions">optional</a>),
	* or if the specified collection is null
	* @see #contains(Object)
	*/
	boolean containsAll(Collection<?> c);

	/**
	* 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 (optional operation). The behavior of this
	* operation is undefined if the specified collection is modified while
	* the operation is in progress. (Note that this will occur if the
	* specified collection is this list, and it's nonempty.)
	*
	* @param c collection containing elements to be added to this list
	* @return {@code true} if this list changed as a result of the call
	* @throws UnsupportedOperationException if the {@code addAll} operation
	* is not supported by this list
	* @throws ClassCastException if the class of an element of the specified
	* collection prevents it from being added to this list
	* @throws NullPointerException if the specified collection contains one
	* or more null elements and this list does not permit null
	* elements, or if the specified collection is null
	* @throws IllegalArgumentException if some property of an element of the
	* specified collection prevents it from being added to this list
	* @see #add(Object)
	*/
	boolean addAll(Collection<? extends E> c);

	/**
	* Inserts all of the elements in the specified collection into this
	* list at the specified position (optional operation). 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. The behavior of this operation is
	* undefined if the specified collection is modified while the
	* operation is in progress. (Note that this will occur if the specified
	* collection is this list, and it's nonempty.)
	*
	* @param index index at which to insert the first element from the
	* specified collection
	* @param c collection containing elements to be added to this list
	* @return {@code true} if this list changed as a result of the call
	* @throws UnsupportedOperationException if the {@code addAll} operation
	* is not supported by this list
	* @throws ClassCastException if the class of an element of the specified
	* collection prevents it from being added to this list
	* @throws NullPointerException if the specified collection contains one
	* or more null elements and this list does not permit null
	* elements, or if the specified collection is null
	* @throws IllegalArgumentException if some property of an element of the
	* specified collection prevents it from being added to this list
	* @throws IndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index > size()})
	*/
	boolean addAll(int index, Collection<? extends E> c);

	/**
	* Removes from this list all of its elements that are contained in the
	* specified collection (optional operation).
	*
	* @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 UnsupportedOperationException if the {@code removeAll} operation
	* is not supported by this list
	* @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 #remove(Object)
	* @see #contains(Object)
	*/
	boolean removeAll(Collection<?> c);

	/**
	* Retains only the elements in this list that are contained in the
	* specified collection (optional operation). 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 UnsupportedOperationException if the {@code retainAll} operation
	* is not supported by this list
	* @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 #remove(Object)
	* @see #contains(Object)
	*/
	boolean retainAll(Collection<?> c);

	/**
	* Replaces each element of this list with the result of applying the
	* operator to that element. Errors or runtime exceptions thrown by
	* the operator are relayed to the caller.
	*
	* @implSpec
	* The default implementation is equivalent to, for this {@code list}:
	* <pre>{@code
	* final ListIterator<E> li = list.listIterator();
	* while (li.hasNext()) {
	* li.set(operator.apply(li.next()));
	* }
	* }</pre>
	*
	* If the list's list-iterator does not support the {@code set} operation
	* then an {@code UnsupportedOperationException} will be thrown when
	* replacing the first element.
	*
	* @param operator the operator to apply to each element
	* @throws UnsupportedOperationException if this list is unmodifiable.
	* Implementations may throw this exception if an element
	* cannot be replaced or if, in general, modification is not
	* supported
	* @throws NullPointerException if the specified operator is null or
	* if the operator result is a null value and this list does
	* not permit null elements
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @since 1.8
	*/
	default void replaceAll(UnaryOperator<E> operator) {
	Objects.requireNonNull(operator);
	final ListIterator<E> li = this.listIterator();
	while (li.hasNext()) {
	li.set(operator.apply(li.next()));
	}
	}

	/**
	* Sorts this list according to the order induced by the specified
	* {@link Comparator}. The sort is <i>stable</i>: this method must not
	* reorder equal elements.
	*
	* <p>All elements in this list must be <i>mutually comparable</i> using the
	* specified comparator (that is, {@code c.compare(e1, e2)} must not throw
	* a {@code ClassCastException} for any elements {@code e1} and {@code e2}
	* in the list).
	*
	* <p>If the specified comparator is {@code null} then all elements in this
	* list must implement the {@link Comparable} interface and the elements'
	* {@linkplain Comparable natural ordering} should be used.
	*
	* <p>This list must be modifiable, but need not be resizable.
	*
	* @implSpec
	* The default implementation obtains an array containing all elements in
	* this list, sorts the array, and iterates over this list resetting each
	* element from the corresponding position in the array. (This avoids the
	* n<sup>2</sup> log(n) performance that would result from attempting
	* to sort a linked list in place.)
	*
	* @implNote
	* This implementation is a stable, adaptive, iterative mergesort that
	* requires far fewer than n lg(n) comparisons when the input array is
	* partially sorted, while offering the performance of a traditional
	* mergesort when the input array is randomly ordered. If the input array
	* is nearly sorted, the implementation requires approximately n
	* comparisons. Temporary storage requirements vary from a small constant
	* for nearly sorted input arrays to n/2 object references for randomly
	* ordered input arrays.
	*
	* <p>The implementation takes equal advantage of ascending and
	* descending order in its input array, and can take advantage of
	* ascending and descending order in different parts of the same
	* input array. It is well-suited to merging two or more sorted arrays:
	* simply concatenate the arrays and sort the resulting array.
	*
	* <p>The implementation was adapted from Tim Peters's list sort for Python
	* (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
	* TimSort</a>). It uses techniques from Peter McIlroy's "Optimistic
	* Sorting and Information Theoretic Complexity", in Proceedings of the
	* Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
	* January 1993.
	*
	* @param c the {@code Comparator} used to compare list elements.
	* A {@code null} value indicates that the elements'
	* {@linkplain Comparable natural ordering} should be used
	* @throws ClassCastException if the list contains elements that are not
	* <i>mutually comparable</i> using the specified comparator
	* @throws UnsupportedOperationException if the list's list-iterator does
	* not support the {@code set} operation
	* @throws IllegalArgumentException
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* if the comparator is found to violate the {@link Comparator}
	* contract
	* @since 1.8
	*/
	@SuppressWarnings({"unchecked", "rawtypes"})
	default void sort(Comparator<? super E> c) {
	Object[] a = this.toArray();
	Arrays.sort(a, (Comparator) c);
	ListIterator<E> i = this.listIterator();
	for (Object e : a) {
	i.next();
	i.set((E) e);
	}
	}

	/**
	* Removes all of the elements from this list (optional operation).
	* The list will be empty after this call returns.
	*
	* @throws UnsupportedOperationException if the {@code clear} operation
	* is not supported by this list
	*/
	void clear();


	// Comparison and hashing

	/**
	* Compares the specified object with this list for equality. Returns
	* {@code 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 <i>equal</i>. (Two elements {@code e1} and
	* {@code e2} are <i>equal</i> if {@code Objects.equals(e1, e2)}.)
	* In other words, two lists are defined to be
	* equal if they contain the same elements in the same order. This
	* definition ensures that the equals method works properly across
	* different implementations of the {@code List} interface.
	*
	* @param o the object to be compared for equality with this list
	* @return {@code true} if the specified object is equal to this list
	*/
	boolean equals(Object o);

	/**
	* Returns the hash code value for this list. The hash code of a list
	* is defined to be the result of the following calculation:
	* <pre>{@code
	* int hashCode = 1;
	* for (E e : list)
	* hashCode = 31*hashCode + (e==null ? 0 : e.hashCode());
	* }</pre>
	* This ensures that {@code list1.equals(list2)} implies that
	* {@code list1.hashCode()==list2.hashCode()} for any two lists,
	* {@code list1} and {@code list2}, as required by the general
	* contract of {@link Object#hashCode}.
	*
	* @return the hash code value for this list
	* @see Object#equals(Object)
	* @see #equals(Object)
	*/
	int hashCode();


	// Positional Access Operations

	/**
	* 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 if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	*/
	E get(int index);

	/**
	* Replaces the element at the specified position in this list with the
	* specified element (optional operation).
	*
	* @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 UnsupportedOperationException if the {@code set} operation
	* is not supported by this list
	* @throws ClassCastException if the class of the specified element
	* prevents it from being added to this list
	* @throws NullPointerException if the specified element is null and
	* this list does not permit null elements
	* @throws IllegalArgumentException if some property of the specified
	* element prevents it from being added to this list
	* @throws IndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	*/
	E set(int index, E element);

	/**
	* Inserts the specified element at the specified position in this list
	* (optional operation). 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 UnsupportedOperationException if the {@code add} operation
	* is not supported by this list
	* @throws ClassCastException if the class of the specified element
	* prevents it from being added to this list
	* @throws NullPointerException if the specified element is null and
	* this list does not permit null elements
	* @throws IllegalArgumentException if some property of the specified
	* element prevents it from being added to this list
	* @throws IndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index > size()})
	*/
	void add(int index, E element);

	/**
	* Removes the element at the specified position in this list (optional
	* operation). Shifts any subsequent elements to the left (subtracts one
	* from their indices). Returns the element that was removed from the
	* list.
	*
	* @param index the index of the element to be removed
	* @return the element previously at the specified position
	* @throws UnsupportedOperationException if the {@code remove} operation
	* is not supported by this list
	* @throws IndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index >= size()})
	*/
	E remove(int index);


	// Search Operations

	/**
	* Returns the index of the first occurrence of the specified element
	* in this list, or -1 if this list does not contain the element.
	* More formally, returns the lowest index {@code i} such that
	* {@code Objects.equals(o, get(i))},
	* or -1 if there is no such index.
	*
	* @param o element to search for
	* @return the index of the first occurrence of the specified element in
	* this list, or -1 if this list does not contain the element
	* @throws ClassCastException if the type of the specified element
	* is incompatible with this list
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if the specified element is null and this
	* list does not permit null elements
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	*/
	int indexOf(Object o);

	/**
	* Returns the index of the last occurrence of the specified element
	* in this list, or -1 if this list does not contain the element.
	* More formally, returns the highest index {@code i} such that
	* {@code Objects.equals(o, get(i))},
	* or -1 if there is no such index.
	*
	* @param o element to search for
	* @return the index of the last occurrence of the specified element in
	* this list, or -1 if this list does not contain the element
	* @throws ClassCastException if the type of the specified element
	* is incompatible with this list
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	* @throws NullPointerException if the specified element is null and this
	* list does not permit null elements
	* (<a href="Collection.html#optional-restrictions">optional</a>)
	*/
	int lastIndexOf(Object o);


	// List Iterators

	/**
	* Returns a list iterator over the elements in this list (in proper
	* sequence).
	*
	* @return a list iterator over the elements in this list (in proper
	* sequence)
	*/
	ListIterator<E> listIterator();

	/**
	* 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.
	*
	* @param index index of the first element to be returned from the
	* list iterator (by a call to {@link ListIterator#next next})
	* @return a list iterator over the elements in this list (in proper
	* sequence), starting at the specified position in the list
	* @throws IndexOutOfBoundsException if the index is out of range
	* ({@code index < 0 \|\| index > size()})
	*/
	ListIterator<E> listIterator(int index);

	// View

	/**
	* 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 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 passing a subList view
	* instead of a whole list. For example, the following idiom
	* removes a range of elements from a list:
	* <pre>{@code
	* list.subList(from, to).clear();
	* }</pre>
	* Similar idioms may be constructed for {@code indexOf} and
	* {@code lastIndexOf}, and all of the algorithms in the
	* {@code 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.)
	*
	* @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 for an illegal endpoint index value
	* ({@code fromIndex < 0 \|\| toIndex > size \|\|
	* fromIndex > toIndex})
	*/
	List<E> subList(int fromIndex, int toIndex);

	/**
	* Creates a {@link Spliterator} over the elements in this list.
	*
	* <p>The {@code Spliterator} reports {@link Spliterator#SIZED} and
	* {@link Spliterator#ORDERED}. Implementations should document the
	* reporting of additional characteristic values.
	*
	* @implSpec
	* The default implementation creates a
	* <em><a href="Spliterator.html#binding">late-binding</a></em>
	* spliterator as follows:
	* <ul>
	* <li>If the list is an instance of {@link RandomAccess} then the default
	* implementation creates a spliterator that traverses elements by
	* invoking the method {@link List#get}. If such invocation results or
	* would result in an {@code IndexOutOfBoundsException} then the
	* spliterator will <em>fail-fast</em> and throw a
	* {@code ConcurrentModificationException}.
	* If the list is also an instance of {@link AbstractList} then the
	* spliterator will use the list's {@link AbstractList#modCount modCount}
	* field to provide additional <em>fail-fast</em> behavior.
	* <li>Otherwise, the default implementation creates a spliterator from the
	* list's {@code Iterator}. The spliterator inherits the
	* <em>fail-fast</em> of the list's iterator.
	* </ul>
	*
	* @implNote
	* The created {@code Spliterator} additionally reports
	* {@link Spliterator#SUBSIZED}.
	*
	* @return a {@code Spliterator} over the elements in this list
	* @since 1.8
	*/
	@Override
	default Spliterator<E> spliterator() {
	if (this instanceof RandomAccess) {
	return new AbstractList.RandomAccessSpliterator<>(this);
	} else {
	return Spliterators.spliterator(this, Spliterator.ORDERED);
	}
	}

	/**
	* Returns an unmodifiable list containing zero elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @return an empty {@code List}
	*
	* @since 9
	*/
	static <E> List<E> of() {
	return ImmutableCollections.emptyList();
	}

	/**
	* Returns an unmodifiable list containing one element.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the single element
	* @return a {@code List} containing the specified element
	* @throws NullPointerException if the element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1) {
	return new ImmutableCollections.List12<>(e1);
	}

	/**
	* Returns an unmodifiable list containing two elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2) {
	return new ImmutableCollections.List12<>(e1, e2);
	}

	/**
	* Returns an unmodifiable list containing three elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @param e3 the third element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2, E e3) {
	return new ImmutableCollections.ListN<>(e1, e2, e3);
	}

	/**
	* Returns an unmodifiable list containing four elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @param e3 the third element
	* @param e4 the fourth element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2, E e3, E e4) {
	return new ImmutableCollections.ListN<>(e1, e2, e3, e4);
	}

	/**
	* Returns an unmodifiable list containing five elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @param e3 the third element
	* @param e4 the fourth element
	* @param e5 the fifth element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2, E e3, E e4, E e5) {
	return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5);
	}

	/**
	* Returns an unmodifiable list containing six elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @param e3 the third element
	* @param e4 the fourth element
	* @param e5 the fifth element
	* @param e6 the sixth element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6) {
	return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
	e6);
	}

	/**
	* Returns an unmodifiable list containing seven elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @param e3 the third element
	* @param e4 the fourth element
	* @param e5 the fifth element
	* @param e6 the sixth element
	* @param e7 the seventh element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7) {
	return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
	e6, e7);
	}

	/**
	* Returns an unmodifiable list containing eight elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @param e3 the third element
	* @param e4 the fourth element
	* @param e5 the fifth element
	* @param e6 the sixth element
	* @param e7 the seventh element
	* @param e8 the eighth element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8) {
	return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
	e6, e7, e8);
	}

	/**
	* Returns an unmodifiable list containing nine elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @param e3 the third element
	* @param e4 the fourth element
	* @param e5 the fifth element
	* @param e6 the sixth element
	* @param e7 the seventh element
	* @param e8 the eighth element
	* @param e9 the ninth element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9) {
	return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
	e6, e7, e8, e9);
	}

	/**
	* Returns an unmodifiable list containing ten elements.
	*
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @param <E> the {@code List}'s element type
	* @param e1 the first element
	* @param e2 the second element
	* @param e3 the third element
	* @param e4 the fourth element
	* @param e5 the fifth element
	* @param e6 the sixth element
	* @param e7 the seventh element
	* @param e8 the eighth element
	* @param e9 the ninth element
	* @param e10 the tenth element
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null}
	*
	* @since 9
	*/
	static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10) {
	return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
	e6, e7, e8, e9, e10);
	}

	/**
	* Returns an unmodifiable list containing an arbitrary number of elements.
	* See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
	*
	* @apiNote
	* This method also accepts a single array as an argument. The element type of
	* the resulting list will be the component type of the array, and the size of
	* the list will be equal to the length of the array. To create a list with
	* a single element that is an array, do the following:
	*
	* <pre>{@code
	* String[] array = ... ;
	* List<String[]> list = List.<String[]>of(array);
	* }</pre>
	*
	* This will cause the {@link List#of(Object) List.of(E)} method
	* to be invoked instead.
	*
	* @param <E> the {@code List}'s element type
	* @param elements the elements to be contained in the list
	* @return a {@code List} containing the specified elements
	* @throws NullPointerException if an element is {@code null} or if the array is {@code null}
	*
	* @since 9
	*/
	@SafeVarargs
	@SuppressWarnings("varargs")
	static <E> List<E> of(E... elements) {
	switch (elements.length) { // implicit null check of elements
	case 0:
	return ImmutableCollections.emptyList();
	case 1:
	return new ImmutableCollections.List12<>(elements[0]);
	case 2:
	return new ImmutableCollections.List12<>(elements[0], elements[1]);
	default:
	return new ImmutableCollections.ListN<>(elements);
	}
	}

	/**
	* Returns an <a href="#unmodifiable">unmodifiable List</a> containing the elements of
	* the given Collection, in its iteration order. The given Collection must not be null,
	* and it must not contain any null elements. If the given Collection is subsequently
	* modified, the returned List will not reflect such modifications.
	*
	* @implNote
	* If the given Collection is an <a href="#unmodifiable">unmodifiable List</a>,
	* calling copyOf will generally not create a copy.
	*
	* @param <E> the {@code List}'s element type
	* @param coll a {@code Collection} from which elements are drawn, must be non-null
	* @return a {@code List} containing the elements of the given {@code Collection}
	* @throws NullPointerException if coll is null, or if it contains any nulls
	* @since 10
	*/
	static <E> List<E> copyOf(Collection<? extends E> coll) {
	return ImmutableCollections.listCopy(coll);
	}
	}

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