src/main/java/org/apache/commons/collections4/list/AbstractLinkedList.java [250:548]:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
            if (fromIndex < 0) {
                throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
            }
            if (toIndex > parent.size()) {
                throw new IndexOutOfBoundsException("toIndex = " + toIndex);
            }
            if (fromIndex > toIndex) {
                throw new IllegalArgumentException("fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
            }
            this.parent = parent;
            this.offset = fromIndex;
            this.size = toIndex - fromIndex;
            this.expectedModCount = parent.modCount;
        }

        @Override
        public void add(final int index, final E obj) {
            rangeCheck(index, size + 1);
            checkModCount();
            parent.add(index + offset, obj);
            expectedModCount = parent.modCount;
            size++;
            modCount++;
        }

        @Override
        public boolean addAll(final Collection<? extends E> coll) {
            return addAll(size, coll);
        }

        @Override
        public boolean addAll(final int index, final Collection<? extends E> coll) {
            rangeCheck(index, size + 1);
            final int cSize = coll.size();
            if (cSize == 0) {
                return false;
            }

            checkModCount();
            parent.addAll(offset + index, coll);
            expectedModCount = parent.modCount;
            size += cSize;
            modCount++;
            return true;
        }

        /**
         * Throws a {@link ConcurrentModificationException} if this instance fails its concurrency check.
         */
        protected void checkModCount() {
            if (parent.modCount != expectedModCount) {
                throw new ConcurrentModificationException();
            }
        }

        @Override
        public void clear() {
            checkModCount();
            final Iterator<E> it = iterator();
            while (it.hasNext()) {
                it.next();
                it.remove();
            }
        }

        @Override
        public E get(final int index) {
            rangeCheck(index, size);
            checkModCount();
            return parent.get(index + offset);
        }

        @Override
        public Iterator<E> iterator() {
            checkModCount();
            return parent.createSubListIterator(this);
        }

        @Override
        public ListIterator<E> listIterator(final int index) {
            rangeCheck(index, size + 1);
            checkModCount();
            return parent.createSubListListIterator(this, index);
        }

        /**
         * Throws an {@link IndexOutOfBoundsException} if the given indices are out of bounds.
         *
         * @param index lower index.
         * @param beyond upper index.
         */
        protected void rangeCheck(final int index, final int beyond) {
            if (index < 0 || index >= beyond) {
                throw new IndexOutOfBoundsException("Index '" + index + "' out of bounds for size '" + size + "'");
            }
        }

        @Override
        public E remove(final int index) {
            rangeCheck(index, size);
            checkModCount();
            final E result = parent.remove(index + offset);
            expectedModCount = parent.modCount;
            size--;
            modCount++;
            return result;
        }

        @Override
        public E set(final int index, final E obj) {
            rangeCheck(index, size);
            checkModCount();
            return parent.set(index + offset, obj);
        }

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

        @Override
        public List<E> subList(final int fromIndexInclusive, final int toIndexExclusive) {
            return new LinkedSubList<>(parent, fromIndexInclusive + offset, toIndexExclusive + offset);
        }
    }

    /**
     * A list iterator over the linked sub list.
     *
     * @param <E> the type of elements in this iterator.
     */
    protected static class LinkedSubListIterator<E> extends LinkedListIterator<E> {

        /** The sub list. */
        protected final LinkedSubList<E> sub;

        /**
         * Constructs a new instance.
         *
         * @param sub The sub-list.
         * @param startIndex The starting index.
         */
        protected LinkedSubListIterator(final LinkedSubList<E> sub, final int startIndex) {
            super(sub.parent, startIndex + sub.offset);
            this.sub = sub;
        }

        @Override
        public void add(final E obj) {
            super.add(obj);
            sub.expectedModCount = parent.modCount;
            sub.size++;
        }

        @Override
        public boolean hasNext() {
            return nextIndex() < sub.size;
        }

        @Override
        public boolean hasPrevious() {
            return previousIndex() >= 0;
        }

        @Override
        public int nextIndex() {
            return super.nextIndex() - sub.offset;
        }

        @Override
        public void remove() {
            super.remove();
            sub.expectedModCount = parent.modCount;
            sub.size--;
        }
    }

    /**
     * A node within the linked list.
     * <p>
     * From Commons Collections 3.1, all access to the {@code value} property
     * is via the methods on this class.
     * </p>
     *
     * @param <E> The node value type.
     */
    protected static class Node<E> {

        /** A pointer to the node before this node */
        protected Node<E> previous;
        /** A pointer to the node after this node */
        protected Node<E> next;
        /** The object contained within this node */
        protected E value;

        /**
         * Constructs a new header node.
         */
        protected Node() {
            previous = this;
            next = this;
        }

        /**
         * Constructs a new node.
         *
         * @param value  the value to store
         */
        protected Node(final E value) {
            this.value = value;
        }

        /**
         * Constructs a new node.
         *
         * @param previous  the previous node in the list
         * @param next  the next node in the list
         * @param value  the value to store
         */
        protected Node(final Node<E> previous, final Node<E> next, final E value) {
            this.previous = previous;
            this.next = next;
            this.value = value;
        }

        /**
         * Gets the next node.
         *
         * @return the next node
         * @since 3.1
         */
        protected Node<E> getNextNode() {
            return next;
        }

        /**
         * Gets the previous node.
         *
         * @return the previous node
         * @since 3.1
         */
        protected Node<E> getPreviousNode() {
            return previous;
        }

        /**
         * Gets the value of the node.
         *
         * @return the value
         * @since 3.1
         */
        protected E getValue() {
            return value;
        }

        /**
         * Sets the next node.
         *
         * @param next  the next node
         * @since 3.1
         */
        protected void setNextNode(final Node<E> next) {
            this.next = next;
        }

        /**
         * Sets the previous node.
         *
         * @param previous  the previous node
         * @since 3.1
         */
        protected void setPreviousNode(final Node<E> previous) {
            this.previous = previous;
        }

        /**
         * Sets the value of the node.
         *
         * @param value  the value
         * @since 3.1
         */
        protected void setValue(final E value) {
            this.value = value;
        }
    }

    /**
     * A {@link Node} which indicates the start and end of the list and does not
     * hold a value. The value of {@code next} is the first item in the
     * list. The value of {@code previous} is the last item in the list.
     */
    transient Node<E> header;

    /** The size of the list */
    transient int size;

    /** Modification count for iterators */
    transient int modCount;
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -



src/main/java/org/apache/commons/collections4/list/AbstractLinkedListJava21.java [249:547]:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
            if (fromIndex < 0) {
                throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
            }
            if (toIndex > parent.size()) {
                throw new IndexOutOfBoundsException("toIndex = " + toIndex);
            }
            if (fromIndex > toIndex) {
                throw new IllegalArgumentException("fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
            }
            this.parent = parent;
            this.offset = fromIndex;
            this.size = toIndex - fromIndex;
            this.expectedModCount = parent.modCount;
        }

        @Override
        public void add(final int index, final E obj) {
            rangeCheck(index, size + 1);
            checkModCount();
            parent.add(index + offset, obj);
            expectedModCount = parent.modCount;
            size++;
            modCount++;
        }

        @Override
        public boolean addAll(final Collection<? extends E> coll) {
            return addAll(size, coll);
        }

        @Override
        public boolean addAll(final int index, final Collection<? extends E> coll) {
            rangeCheck(index, size + 1);
            final int cSize = coll.size();
            if (cSize == 0) {
                return false;
            }

            checkModCount();
            parent.addAll(offset + index, coll);
            expectedModCount = parent.modCount;
            size += cSize;
            modCount++;
            return true;
        }

        /**
         * Throws a {@link ConcurrentModificationException} if this instance fails its concurrency check.
         */
        protected void checkModCount() {
            if (parent.modCount != expectedModCount) {
                throw new ConcurrentModificationException();
            }
        }

        @Override
        public void clear() {
            checkModCount();
            final Iterator<E> it = iterator();
            while (it.hasNext()) {
                it.next();
                it.remove();
            }
        }

        @Override
        public E get(final int index) {
            rangeCheck(index, size);
            checkModCount();
            return parent.get(index + offset);
        }

        @Override
        public Iterator<E> iterator() {
            checkModCount();
            return parent.createSubListIterator(this);
        }

        @Override
        public ListIterator<E> listIterator(final int index) {
            rangeCheck(index, size + 1);
            checkModCount();
            return parent.createSubListListIterator(this, index);
        }

        /**
         * Throws an {@link IndexOutOfBoundsException} if the given indices are out of bounds.
         *
         * @param index lower index.
         * @param beyond upper index.
         */
        protected void rangeCheck(final int index, final int beyond) {
            if (index < 0 || index >= beyond) {
                throw new IndexOutOfBoundsException("Index '" + index + "' out of bounds for size '" + size + "'");
            }
        }

        @Override
        public E remove(final int index) {
            rangeCheck(index, size);
            checkModCount();
            final E result = parent.remove(index + offset);
            expectedModCount = parent.modCount;
            size--;
            modCount++;
            return result;
        }

        @Override
        public E set(final int index, final E obj) {
            rangeCheck(index, size);
            checkModCount();
            return parent.set(index + offset, obj);
        }

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

        @Override
        public List<E> subList(final int fromIndexInclusive, final int toIndexExclusive) {
            return new LinkedSubList<>(parent, fromIndexInclusive + offset, toIndexExclusive + offset);
        }
    }

    /**
     * A list iterator over the linked sub list.
     *
     * @param <E> the type of elements in this iterator.
     */
    protected static class LinkedSubListIterator<E> extends LinkedListIterator<E> {

        /** The sub list */
        protected final LinkedSubList<E> sub;

        /**
         * Constructs a new instance.
         *
         * @param sub The sub-list.
         * @param startIndex The starting index.
         */
        protected LinkedSubListIterator(final LinkedSubList<E> sub, final int startIndex) {
            super(sub.parent, startIndex + sub.offset);
            this.sub = sub;
        }

        @Override
        public void add(final E obj) {
            super.add(obj);
            sub.expectedModCount = parent.modCount;
            sub.size++;
        }

        @Override
        public boolean hasNext() {
            return nextIndex() < sub.size;
        }

        @Override
        public boolean hasPrevious() {
            return previousIndex() >= 0;
        }

        @Override
        public int nextIndex() {
            return super.nextIndex() - sub.offset;
        }

        @Override
        public void remove() {
            super.remove();
            sub.expectedModCount = parent.modCount;
            sub.size--;
        }
    }

    /**
     * A node within the linked list.
     * <p>
     * From Commons Collections 3.1, all access to the {@code value} property
     * is via the methods on this class.
     * </p>
     *
     * @param <E> the type of the node value.
     */
    protected static class Node<E> {

        /** A pointer to the node before this node */
        protected Node<E> previous;
        /** A pointer to the node after this node */
        protected Node<E> next;
        /** The object contained within this node */
        protected E value;

        /**
         * Constructs a new header node.
         */
        protected Node() {
            previous = this;
            next = this;
        }

        /**
         * Constructs a new node.
         *
         * @param value  the value to store
         */
        protected Node(final E value) {
            this.value = value;
        }

        /**
         * Constructs a new node.
         *
         * @param previous  the previous node in the list
         * @param next  the next node in the list
         * @param value  the value to store
         */
        protected Node(final Node<E> previous, final Node<E> next, final E value) {
            this.previous = previous;
            this.next = next;
            this.value = value;
        }

        /**
         * Gets the next node.
         *
         * @return the next node
         * @since 3.1
         */
        protected Node<E> getNextNode() {
            return next;
        }

        /**
         * Gets the previous node.
         *
         * @return the previous node
         * @since 3.1
         */
        protected Node<E> getPreviousNode() {
            return previous;
        }

        /**
         * Gets the value of the node.
         *
         * @return the value
         * @since 3.1
         */
        protected E getValue() {
            return value;
        }

        /**
         * Sets the next node.
         *
         * @param next  the next node
         * @since 3.1
         */
        protected void setNextNode(final Node<E> next) {
            this.next = next;
        }

        /**
         * Sets the previous node.
         *
         * @param previous  the previous node
         * @since 3.1
         */
        protected void setPreviousNode(final Node<E> previous) {
            this.previous = previous;
        }

        /**
         * Sets the value of the node.
         *
         * @param value  the value
         * @since 3.1
         */
        protected void setValue(final E value) {
            this.value = value;
        }
    }

    /**
     * A {@link Node} which indicates the start and end of the list and does not
     * hold a value. The value of {@code next} is the first item in the
     * list. The value of {@code previous} is the last item in the list.
     */
    transient Node<E> header;

    /** The size of the list */
    transient int size;

    /** Modification count for iterators */
    transient int modCount;
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -