Definitions.java

    /**
     * Attempts to add a Shape to a NestingShape object. If successful, a
     * two-way link is established between the NestingShape and the newly-added
     * Shape. Note that this method has package visibility.
     * @param shape the shape to be added.
     * @throws IllegalArgumentException if an attempt is made to add a Shape
     * that will not fit within the bounds of the proposed NestingShape object.
     */
    void add(Shape shape) throws IllegalArgumentException {

    }
    
    /**
     * Removes a particular Shape from a NestingShape instance. Once removed,
     * the two-way link between the NestingShape and its former child is
     * destroyed. This method has no effect if the Shape specified to remove
     * is not a child of the NestingShape. Note that this method has package
     * visibility.
     * @param shape the shape to be removed. 
     */
    void remove(Shape shape) {

    }

    /**
     * Returns the Shape at a specified position within a NestingShape. If
     * the position specified is less than zero or greater than the number of
     * children stored in the NestingShape less one this method thows an
     * IndexOutOfBoundsException.
     * @param index the specified index position.
     */
    public Shape shapeAt(int index) throws IndexOutOfBoundsException {

    }

    /**
     * Returns the number of children contained within a NestingShape object.
     * Note this method is not recursive -- it simply returns the number of 
     * children at the top level within the callee NestingShape object.
     */
    public int shapeCount() {

    }

    /**
     * Returns the index of a specified child within a NestingShape object.
     * If the Shape specified is not actually a child of the NestingShape
     * this method returns -1; otherwise the value returned is in the range
     * 0 .. shapeCount() - 1.
     * @param shape the shape whose index position within the NestingShape is
     * requested.
     */
    public int indexOf(Shape shape) {

    }

    /**
     * Returns true if the Shape argument is a child of the NestingShape
     * object on which this method is called, false otherwise.
     */
    public boolean contains(Shape shape) {

    }

    /**
     * Returns the NestingShape that contains the Shape that method parent
     * is called on. If the callee object is not a child within a
     * NestingShape instance this method returns null.
     */
    public NestingShape parent() {

    }

    /**
     * Returns an ordered list of Shape objects. The first item within
     * the list is the root NestingShape of the containment hierarchy.
     * The last item within the list is the callee object (hence this
     * method always returns a list with at least one item). Any 
     * intermediate items are NestingShapes that connect the root 
     * NestingShape to the callee Shape. E.g., given:
     * 
     *		NestingShape root = new NestingShape();
     *		NestingShape intermediate = new NestingShape();
     * 		Shape oval = new OvalShape();
     * 		root.add(intermediate);
     * 		intermediate.add(oval);
     *
     * a call to oval.path() yields: [root, intermediate, oval].
     */
    public List<Shape> path() {

    }