@Pure
	public final N getChildAt(BinaryTreeZone index) {
		switch (index) {
		case LEFT:
			return this.left;
		case RIGHT:
			return this.right;
		default:
			throw new IndexOutOfBoundsException();
		}
	}
@ Pure public final N getChildAt ( BinaryTreeZone index ) { switch ( index ) { case LEFT : return this . left ; case RIGHT : return this . right ; default : throw new IndexOutOfBoundsException ( ) ; } }
Replies the child node at the specified position.

@param index is the position of the child to reply.
@return the child or <code>null</code>