src/main/java/org/apache/commons/collections4/list/AbstractLinkedList.java [624:1139]:
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    protected void addNode(final Node<E> nodeToInsert, final Node<E> insertBeforeNode) {
        Objects.requireNonNull(nodeToInsert, "nodeToInsert");
        Objects.requireNonNull(insertBeforeNode, "insertBeforeNode");
        nodeToInsert.next = insertBeforeNode;
        nodeToInsert.previous = insertBeforeNode.previous;
        insertBeforeNode.previous.next = nodeToInsert;
        insertBeforeNode.previous = nodeToInsert;
        size++;
        modCount++;
    }

    /**
     * Creates a new node with the specified object as its
     * {@code value} and inserts it after {@code node}.
     * <p>
     * This implementation uses {@link #createNode(Object)} and
     * {@link #addNode(AbstractLinkedList.Node,AbstractLinkedList.Node)}.
     *
     * @param node  node to insert after
     * @param value  value of the newly added node
     * @throws NullPointerException if {@code node} is null
     */
    protected void addNodeAfter(final Node<E> node, final E value) {
        final Node<E> newNode = createNode(value);
        addNode(newNode, node.next);
    }

    /**
     * Creates a new node with the specified object as its
     * {@code value} and inserts it before {@code node}.
     * <p>
     * This implementation uses {@link #createNode(Object)} and
     * {@link #addNode(AbstractLinkedList.Node,AbstractLinkedList.Node)}.
     *
     * @param node  node to insert before
     * @param value  value of the newly added node
     * @throws NullPointerException if {@code node} is null
     */
    protected void addNodeBefore(final Node<E> node, final E value) {
        final Node<E> newNode = createNode(value);
        addNode(newNode, node);
    }

    @Override
    public void clear() {
        removeAllNodes();
    }

    @Override
    public boolean contains(final Object value) {
        return indexOf(value) != -1;
    }

    @Override
    public boolean containsAll(final Collection<?> coll) {
        for (final Object o : coll) {
            if (!contains(o)) {
                return false;
            }
        }
        return true;
    }

    /**
     * Creates a new node with previous, next and element all set to null.
     * This implementation creates a new empty Node.
     * Subclasses can override this to create a different class.
     *
     * @return  newly created node
     */
    protected Node<E> createHeaderNode() {
        return new Node<>();
    }

    /**
     * Creates a new node with the specified properties.
     * This implementation creates a new Node with data.
     * Subclasses can override this to create a different class.
     *
     * @param value  value of the new node
     * @return a new node containing the value
     */
    protected Node<E> createNode(final E value) {
        return new Node<>(value);
    }

    /**
     * Creates an iterator for the sublist.
     *
     * @param subList  the sublist to get an iterator for
     * @return a new iterator on the given sublist
     */
    protected Iterator<E> createSubListIterator(final LinkedSubList<E> subList) {
        return createSubListListIterator(subList, 0);
    }

    /**
     * Creates a list iterator for the sublist.
     *
     * @param subList  the sublist to get an iterator for
     * @param fromIndex  the index to start from, relative to the sublist
     * @return a new list iterator on the given sublist
     */
    protected ListIterator<E> createSubListListIterator(final LinkedSubList<E> subList, final int fromIndex) {
        return new LinkedSubListIterator<>(subList, fromIndex);
    }

    /**
     * Deserializes the data held in this object to the stream specified.
     * <p>
     * The first serializable subclass must call this method from
     * {@code readObject}.
     *
     * @param inputStream  the stream to read the object from
     * @throws IOException  if any error occurs while reading from the stream
     * @throws ClassNotFoundException  if a class read from the stream cannot be loaded
     */
    @SuppressWarnings("unchecked")
    protected void doReadObject(final ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
        init();
        final int size = inputStream.readInt();
        for (int i = 0; i < size; i++) {
            add((E) inputStream.readObject());
        }
    }

    /**
     * Serializes the data held in this object to the stream specified.
     * <p>
     * The first serializable subclass must call this method from
     * {@code writeObject}.
     *
     * @param outputStream  the stream to write the object to
     * @throws IOException  if anything goes wrong
     */
    protected void doWriteObject(final ObjectOutputStream outputStream) throws IOException {
        // Write the size so we know how many nodes to read back
        outputStream.writeInt(size());
        for (final E e : this) {
            outputStream.writeObject(e);
        }
    }

    @Override
    public boolean equals(final Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof List)) {
            return false;
        }
        final List<?> other = (List<?>) obj;
        if (other.size() != size()) {
            return false;
        }
        final ListIterator<?> it1 = listIterator();
        final ListIterator<?> it2 = other.listIterator();
        while (it1.hasNext() && it2.hasNext()) {
            if (!Objects.equals(it1.next(), it2.next())) {
                return false;
            }
        }
        return !(it1.hasNext() || it2.hasNext());
    }

    @Override
    public E get(final int index) {
        final Node<E> node = getNode(index, false);
        return node.getValue();
    }

    /**
     * Gets the first element.
     *
     * @return the first element.
     */
    public E getFirst() {
        final Node<E> node = header.next;
        if (node == header) {
            throw new NoSuchElementException();
        }
        return node.getValue();
    }

    /**
     * Gets the last element.
     *
     * @return the last element.
     */
    public E getLast() {
        final Node<E> node = header.previous;
        if (node == header) {
            throw new NoSuchElementException();
        }
        return node.getValue();
    }

    /**
     * Gets the node at a particular index.
     *
     * @param index  the index, starting from 0
     * @param endMarkerAllowed  whether or not the end marker can be returned if
     * startIndex is set to the list's size
     * @return the node at the given index
     * @throws IndexOutOfBoundsException if the index is less than 0; equal to
     * the size of the list and endMakerAllowed is false; or greater than the
     * size of the list
     */
    protected Node<E> getNode(final int index, final boolean endMarkerAllowed) throws IndexOutOfBoundsException {
        // Check the index is within the bounds
        if (index < 0) {
            throw new IndexOutOfBoundsException("Couldn't get the node: " +
                    "index (" + index + ") less than zero.");
        }
        if (!endMarkerAllowed && index == size) {
            throw new IndexOutOfBoundsException("Couldn't get the node: " +
                    "index (" + index + ") is the size of the list.");
        }
        if (index > size) {
            throw new IndexOutOfBoundsException("Couldn't get the node: " +
                    "index (" + index + ") greater than the size of the " +
                    "list (" + size + ").");
        }
        // Search the list and get the node
        Node<E> node;
        if (index < size / 2) {
            // Search forwards
            node = header.next;
            for (int currentIndex = 0; currentIndex < index; currentIndex++) {
                node = node.next;
            }
        } else {
            // Search backwards
            node = header;
            for (int currentIndex = size; currentIndex > index; currentIndex--) {
                node = node.previous;
            }
        }
        return node;
    }

    @Override
    public int hashCode() {
        int hashCode = 1;
        for (final E e : this) {
            hashCode = 31 * hashCode + (e == null ? 0 : e.hashCode());
        }
        return hashCode;
    }

    @Override
    public int indexOf(final Object value) {
        int i = 0;
        for (Node<E> node = header.next; node != header; node = node.next) {
            if (isEqualValue(node.getValue(), value)) {
                return i;
            }
            i++;
        }
        return CollectionUtils.INDEX_NOT_FOUND;
    }

    /**
     * The equivalent of a default constructor, broken out so it can be called
     * by any constructor and by {@code readObject}.
     * Subclasses which override this method should make sure they call super,
     * so the list is initialized properly.
     */
    protected void init() {
        header = createHeaderNode();
    }

    @Override
    public boolean isEmpty() {
        return size() == 0;
    }

    /**
     * Compares two values for equals.
     * This implementation uses the equals method.
     * Subclasses can override this to match differently.
     *
     * @param value1  the first value to compare, may be null
     * @param value2  the second value to compare, may be null
     * @return true if equal
     */
    protected boolean isEqualValue(final Object value1, final Object value2) {
        return Objects.equals(value1, value2);
    }

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

    @Override
    public int lastIndexOf(final Object value) {
        int i = size - 1;
        for (Node<E> node = header.previous; node != header; node = node.previous) {
            if (isEqualValue(node.getValue(), value)) {
                return i;
            }
            i--;
        }
        return CollectionUtils.INDEX_NOT_FOUND;
    }

    @Override
    public ListIterator<E> listIterator() {
        return new LinkedListIterator<>(this, 0);
    }

    @Override
    public ListIterator<E> listIterator(final int fromIndex) {
        return new LinkedListIterator<>(this, fromIndex);
    }

    @Override
    public E remove(final int index) {
        final Node<E> node = getNode(index, false);
        final E oldValue = node.getValue();
        removeNode(node);
        return oldValue;
    }

    @Override
    public boolean remove(final Object value) {
        for (Node<E> node = header.next; node != header; node = node.next) {
            if (isEqualValue(node.getValue(), value)) {
                removeNode(node);
                return true;
            }
        }
        return false;
    }

    /**
     * {@inheritDoc}
     * <p>
     * This implementation iterates over the elements of this list, checking each element in
     * turn to see if it's contained in {@code coll}. If it's contained, it's removed
     * from this list. As a consequence, it is advised to use a collection type for
     * {@code coll} that provides a fast (for example O(1)) implementation of
     * {@link Collection#contains(Object)}.
     */
    @Override
    public boolean removeAll(final Collection<?> coll) {
        boolean modified = false;
        final Iterator<E> it = iterator();
        while (it.hasNext()) {
            if (coll.contains(it.next())) {
                it.remove();
                modified = true;
            }
        }
        return modified;
    }

    /**
     * Removes all nodes by resetting the circular list marker.
     */
    protected void removeAllNodes() {
        header.next = header;
        header.previous = header;
        size = 0;
        modCount++;
    }

    /**
     * Removes the first element.
     *
     * @return The value removed.
     */
    public E removeFirst() {
        final Node<E> node = header.next;
        if (node == header) {
            throw new NoSuchElementException();
        }
        final E oldValue = node.getValue();
        removeNode(node);
        return oldValue;
    }

    /**
     * Removes the last element.
     *
     * @return The value removed.
     */
    public E removeLast() {
        final Node<E> node = header.previous;
        if (node == header) {
            throw new NoSuchElementException();
        }
        final E oldValue = node.getValue();
        removeNode(node);
        return oldValue;
    }

    /**
     * Removes the specified node from the list.
     *
     * @param node  the node to remove
     * @throws NullPointerException if {@code node} is null
     */
    protected void removeNode(final Node<E> node) {
        Objects.requireNonNull(node, "node");
        node.previous.next = node.next;
        node.next.previous = node.previous;
        size--;
        modCount++;
    }

    /**
     * {@inheritDoc}
     * <p>
     * This implementation iterates over the elements of this list, checking each element in
     * turn to see if it's contained in {@code coll}. If it's not contained, it's removed
     * from this list. As a consequence, it is advised to use a collection type for
     * {@code coll} that provides a fast (for example O(1)) implementation of
     * {@link Collection#contains(Object)}.
     */
    @Override
    public boolean retainAll(final Collection<?> coll) {
        boolean modified = false;
        final Iterator<E> it = iterator();
        while (it.hasNext()) {
            if (!coll.contains(it.next())) {
                it.remove();
                modified = true;
            }
        }
        return modified;
    }

    @Override
    public E set(final int index, final E value) {
        final Node<E> node = getNode(index, false);
        final E oldValue = node.getValue();
        updateNode(node, value);
        return oldValue;
    }

    @Override
    public int size() {
        return size;
    }

    /**
     * Gets a sublist of the main list.
     *
     * @param fromIndexInclusive  the index to start from
     * @param toIndexExclusive  the index to end at
     * @return the new sublist
     */
    @Override
    public List<E> subList(final int fromIndexInclusive, final int toIndexExclusive) {
        return new LinkedSubList<>(this, fromIndexInclusive, toIndexExclusive);
    }

    @Override
    public Object[] toArray() {
        return toArray(new Object[size]);
    }

    @Override
    @SuppressWarnings("unchecked")
    public <T> T[] toArray(T[] array) {
        // Extend the array if needed
        if (array.length < size) {
            final Class<?> componentType = array.getClass().getComponentType();
            array = (T[]) Array.newInstance(componentType, size);
        }
        // Copy the values into the array
        int i = 0;
        for (Node<E> node = header.next; node != header; node = node.next, i++) {
            array[i] = (T) node.getValue();
        }
        // Set the value after the last value to null
        if (array.length > size) {
            array[size] = null;
        }
        return array;
    }

    @Override
    public String toString() {
        if (isEmpty()) {
            return "[]";
        }
        final StringBuilder buf = new StringBuilder(16 * size());
        buf.append(CollectionUtils.DEFAULT_TOSTRING_PREFIX);

        final Iterator<E> it = iterator();
        boolean hasNext = it.hasNext();
        while (hasNext) {
            final Object value = it.next();
            buf.append(value == this ? "(this Collection)" : value);
            hasNext = it.hasNext();
            if (hasNext) {
                buf.append(", ");
            }
        }
        buf.append(CollectionUtils.DEFAULT_TOSTRING_SUFFIX);
        return buf.toString();
    }

    /**
     * Updates the node with a new value.
     * This implementation sets the value on the node.
     * Subclasses can override this to record the change.
     *
     * @param node  node to update
     * @param value  new value of the node
     */
    protected void updateNode(final Node<E> node, final E value) {
        node.setValue(value);
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src/main/java/org/apache/commons/collections4/list/AbstractLinkedListJava21.java [616:1129]:
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    protected void addNode(final Node<E> nodeToInsert, final Node<E> insertBeforeNode) {
        Objects.requireNonNull(nodeToInsert, "nodeToInsert");
        Objects.requireNonNull(insertBeforeNode, "insertBeforeNode");
        nodeToInsert.next = insertBeforeNode;
        nodeToInsert.previous = insertBeforeNode.previous;
        insertBeforeNode.previous.next = nodeToInsert;
        insertBeforeNode.previous = nodeToInsert;
        size++;
        modCount++;
    }

    /**
     * Creates a new node with the specified object as its
     * {@code value} and inserts it after {@code node}.
     * <p>
     * This implementation uses {@link #createNode(Object)} and
     * {@link #addNode(AbstractLinkedListJava21.Node,AbstractLinkedListJava21.Node)}.
     * </p>
     *
     * @param node  node to insert after
     * @param value  value of the newly added node
     * @throws NullPointerException if {@code node} is null
     */
    protected void addNodeAfter(final Node<E> node, final E value) {
        final Node<E> newNode = createNode(value);
        addNode(newNode, node.next);
    }

    /**
     * Creates a new node with the specified object as its
     * {@code value} and inserts it before {@code node}.
     * <p>
     * This implementation uses {@link #createNode(Object)} and
     * {@link #addNode(AbstractLinkedListJava21.Node,AbstractLinkedListJava21.Node)}.
     * </p>
     *
     * @param node  node to insert before
     * @param value  value of the newly added node
     * @throws NullPointerException if {@code node} is null
     */
    protected void addNodeBefore(final Node<E> node, final E value) {
        final Node<E> newNode = createNode(value);
        addNode(newNode, node);
    }

    @Override
    public void clear() {
        removeAllNodes();
    }

    @Override
    public boolean contains(final Object value) {
        return indexOf(value) != -1;
    }

    @Override
    public boolean containsAll(final Collection<?> coll) {
        for (final Object o : coll) {
            if (!contains(o)) {
                return false;
            }
        }
        return true;
    }

    /**
     * Creates a new node with previous, next and element all set to null.
     * This implementation creates a new empty Node.
     * Subclasses can override this to create a different class.
     *
     * @return  newly created node
     */
    protected Node<E> createHeaderNode() {
        return new Node<>();
    }

    /**
     * Creates a new node with the specified properties.
     * This implementation creates a new Node with data.
     * Subclasses can override this to create a different class.
     *
     * @param value  value of the new node
     * @return a new node containing the value
     */
    protected Node<E> createNode(final E value) {
        return new Node<>(value);
    }

    /**
     * Creates an iterator for the sublist.
     *
     * @param subList  the sublist to get an iterator for
     * @return a new iterator on the given sublist
     */
    protected Iterator<E> createSubListIterator(final LinkedSubList<E> subList) {
        return createSubListListIterator(subList, 0);
    }

    /**
     * Creates a list iterator for the sublist.
     *
     * @param subList  the sublist to get an iterator for
     * @param fromIndex  the index to start from, relative to the sublist
     * @return a new list iterator on the given sublist
     */
    protected ListIterator<E> createSubListListIterator(final LinkedSubList<E> subList, final int fromIndex) {
        return new LinkedSubListIterator<>(subList, fromIndex);
    }

    /**
     * Deserializes the data held in this object to the stream specified.
     * <p>
     * The first serializable subclass must call this method from
     * {@code readObject}.
     * </p>
     *
     * @param inputStream  the stream to read the object from
     * @throws IOException  if any error occurs while reading from the stream
     * @throws ClassNotFoundException  if a class read from the stream cannot be loaded
     */
    @SuppressWarnings("unchecked")
    protected void doReadObject(final ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
        init();
        final int size = inputStream.readInt();
        for (int i = 0; i < size; i++) {
            add((E) inputStream.readObject());
        }
    }

    /**
     * Serializes the data held in this object to the stream specified.
     * <p>
     * The first serializable subclass must call this method from
     * {@code writeObject}.
     * </p>
     *
     * @param outputStream  the stream to write the object to
     * @throws IOException  if anything goes wrong
     */
    protected void doWriteObject(final ObjectOutputStream outputStream) throws IOException {
        // Write the size so we know how many nodes to read back
        outputStream.writeInt(size());
        for (final E e : this) {
            outputStream.writeObject(e);
        }
    }

    @Override
    public boolean equals(final Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof List)) {
            return false;
        }
        final List<?> other = (List<?>) obj;
        if (other.size() != size()) {
            return false;
        }
        final ListIterator<?> it1 = listIterator();
        final ListIterator<?> it2 = other.listIterator();
        while (it1.hasNext() && it2.hasNext()) {
            if (!Objects.equals(it1.next(), it2.next())) {
                return false;
            }
        }
        return !(it1.hasNext() || it2.hasNext());
    }

    @Override
    public E get(final int index) {
        final Node<E> node = getNode(index, false);
        return node.getValue();
    }

    /**
     * {@inheritDoc}
     */
    public E getFirst() {
        final Node<E> node = header.next;
        if (node == header) {
            throw new NoSuchElementException();
        }
        return node.getValue();
    }

    /**
     * {@inheritDoc}
     */
    public E getLast() {
        final Node<E> node = header.previous;
        if (node == header) {
            throw new NoSuchElementException();
        }
        return node.getValue();
    }

    /**
     * Gets the node at a particular index.
     *
     * @param index  the index, starting from 0
     * @param endMarkerAllowed  whether or not the end marker can be returned if
     * startIndex is set to the list's size
     * @return the node at the given index
     * @throws IndexOutOfBoundsException if the index is less than 0; equal to
     * the size of the list and endMakerAllowed is false; or greater than the
     * size of the list
     */
    protected Node<E> getNode(final int index, final boolean endMarkerAllowed) throws IndexOutOfBoundsException {
        // Check the index is within the bounds
        if (index < 0) {
            throw new IndexOutOfBoundsException("Couldn't get the node: " +
                    "index (" + index + ") less than zero.");
        }
        if (!endMarkerAllowed && index == size) {
            throw new IndexOutOfBoundsException("Couldn't get the node: " +
                    "index (" + index + ") is the size of the list.");
        }
        if (index > size) {
            throw new IndexOutOfBoundsException("Couldn't get the node: " +
                    "index (" + index + ") greater than the size of the " +
                    "list (" + size + ").");
        }
        // Search the list and get the node
        Node<E> node;
        if (index < size / 2) {
            // Search forwards
            node = header.next;
            for (int currentIndex = 0; currentIndex < index; currentIndex++) {
                node = node.next;
            }
        } else {
            // Search backwards
            node = header;
            for (int currentIndex = size; currentIndex > index; currentIndex--) {
                node = node.previous;
            }
        }
        return node;
    }

    @Override
    public int hashCode() {
        int hashCode = 1;
        for (final E e : this) {
            hashCode = 31 * hashCode + (e == null ? 0 : e.hashCode());
        }
        return hashCode;
    }

    @Override
    public int indexOf(final Object value) {
        int i = 0;
        for (Node<E> node = header.next; node != header; node = node.next) {
            if (isEqualValue(node.getValue(), value)) {
                return i;
            }
            i++;
        }
        return CollectionUtils.INDEX_NOT_FOUND;
    }

    /**
     * The equivalent of a default constructor, broken out so it can be called
     * by any constructor and by {@code readObject}.
     * Subclasses which override this method should make sure they call super,
     * so the list is initialized properly.
     */
    protected void init() {
        header = createHeaderNode();
    }

    @Override
    public boolean isEmpty() {
        return size() == 0;
    }

    /**
     * Compares two values for equals.
     * This implementation uses the equals method.
     * Subclasses can override this to match differently.
     *
     * @param value1  the first value to compare, may be null
     * @param value2  the second value to compare, may be null
     * @return true if equal
     */
    protected boolean isEqualValue(final Object value1, final Object value2) {
        return Objects.equals(value1, value2);
    }

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

    @Override
    public int lastIndexOf(final Object value) {
        int i = size - 1;
        for (Node<E> node = header.previous; node != header; node = node.previous) {
            if (isEqualValue(node.getValue(), value)) {
                return i;
            }
            i--;
        }
        return CollectionUtils.INDEX_NOT_FOUND;
    }

    @Override
    public ListIterator<E> listIterator() {
        return new LinkedListIterator<>(this, 0);
    }

    @Override
    public ListIterator<E> listIterator(final int fromIndex) {
        return new LinkedListIterator<>(this, fromIndex);
    }

    @Override
    public E remove(final int index) {
        final Node<E> node = getNode(index, false);
        final E oldValue = node.getValue();
        removeNode(node);
        return oldValue;
    }

    @Override
    public boolean remove(final Object value) {
        for (Node<E> node = header.next; node != header; node = node.next) {
            if (isEqualValue(node.getValue(), value)) {
                removeNode(node);
                return true;
            }
        }
        return false;
    }

    /**
     * {@inheritDoc}
     * <p>
     * This implementation iterates over the elements of this list, checking each element in
     * turn to see if it's contained in {@code coll}. If it's contained, it's removed
     * from this list. As a consequence, it is advised to use a collection type for
     * {@code coll} that provides a fast (for example O(1)) implementation of
     * {@link Collection#contains(Object)}.
     * </p>
     */
    @Override
    public boolean removeAll(final Collection<?> coll) {
        boolean modified = false;
        final Iterator<E> it = iterator();
        while (it.hasNext()) {
            if (coll.contains(it.next())) {
                it.remove();
                modified = true;
            }
        }
        return modified;
    }

    /**
     * Removes all nodes by resetting the circular list marker.
     */
    protected void removeAllNodes() {
        header.next = header;
        header.previous = header;
        size = 0;
        modCount++;
    }

    /**
     * {@inheritDoc}
     */
    public E removeFirst() {
        final Node<E> node = header.next;
        if (node == header) {
            throw new NoSuchElementException();
        }
        final E oldValue = node.getValue();
        removeNode(node);
        return oldValue;
    }

    /**
     * {@inheritDoc}
     */
    public E removeLast() {
        final Node<E> node = header.previous;
        if (node == header) {
            throw new NoSuchElementException();
        }
        final E oldValue = node.getValue();
        removeNode(node);
        return oldValue;
    }

    /**
     * Removes the specified node from the list.
     *
     * @param node  the node to remove
     * @throws NullPointerException if {@code node} is null
     */
    protected void removeNode(final Node<E> node) {
        Objects.requireNonNull(node, "node");
        node.previous.next = node.next;
        node.next.previous = node.previous;
        size--;
        modCount++;
    }

    /**
     * {@inheritDoc}
     * <p>
     * This implementation iterates over the elements of this list, checking each element in
     * turn to see if it's contained in {@code coll}. If it's not contained, it's removed
     * from this list. As a consequence, it is advised to use a collection type for
     * {@code coll} that provides a fast (for example O(1)) implementation of
     * {@link Collection#contains(Object)}.
     * </p>
     */
    @Override
    public boolean retainAll(final Collection<?> coll) {
        boolean modified = false;
        final Iterator<E> it = iterator();
        while (it.hasNext()) {
            if (!coll.contains(it.next())) {
                it.remove();
                modified = true;
            }
        }
        return modified;
    }

    @Override
    public E set(final int index, final E value) {
        final Node<E> node = getNode(index, false);
        final E oldValue = node.getValue();
        updateNode(node, value);
        return oldValue;
    }

    @Override
    public int size() {
        return size;
    }

    /**
     * Gets a sublist of the main list.
     *
     * @param fromIndexInclusive  the index to start from
     * @param toIndexExclusive  the index to end at
     * @return the new sublist
     */
    @Override
    public List<E> subList(final int fromIndexInclusive, final int toIndexExclusive) {
        return new LinkedSubList<>(this, fromIndexInclusive, toIndexExclusive);
    }

    @Override
    public Object[] toArray() {
        return toArray(new Object[size]);
    }

    @Override
    @SuppressWarnings("unchecked")
    public <T> T[] toArray(T[] array) {
        // Extend the array if needed
        if (array.length < size) {
            final Class<?> componentType = array.getClass().getComponentType();
            array = (T[]) Array.newInstance(componentType, size);
        }
        // Copy the values into the array
        int i = 0;
        for (Node<E> node = header.next; node != header; node = node.next, i++) {
            array[i] = (T) node.getValue();
        }
        // Set the value after the last value to null
        if (array.length > size) {
            array[size] = null;
        }
        return array;
    }

    @Override
    public String toString() {
        if (isEmpty()) {
            return "[]";
        }
        final StringBuilder buf = new StringBuilder(16 * size());
        buf.append(CollectionUtils.DEFAULT_TOSTRING_PREFIX);

        final Iterator<E> it = iterator();
        boolean hasNext = it.hasNext();
        while (hasNext) {
            final Object value = it.next();
            buf.append(value == this ? "(this Collection)" : value);
            hasNext = it.hasNext();
            if (hasNext) {
                buf.append(", ");
            }
        }
        buf.append(CollectionUtils.DEFAULT_TOSTRING_SUFFIX);
        return buf.toString();
    }

    /**
     * Updates the node with a new value.
     * This implementation sets the value on the node.
     * Subclasses can override this to record the change.
     *
     * @param node  node to update
     * @param value  new value of the node
     */
    protected void updateNode(final Node<E> node, final E value) {
        node.setValue(value);
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