////   This file contains the C++ code from Program 10.9 of//   "Data Structures and Algorithms//    with Object-Oriented Design Patterns in C++"//   by Bruno R. Preiss.////   Copyright (c) 1998 by Bruno R. Preiss, P.Eng.  All rights reserved.////   http://www.pads.uwaterloo.ca/Bruno.Preiss/books/opus4/programs/pgm10_09.cpp//void AVLTree::LLRotation (){    if (IsEmpty ())	throw domain_error ("invalid rotation");    BinaryTree* const tmp = right;    right = left;    left = Right ().left;    Right ().left = Right ().right;    Right ().right = tmp;    Object* const tmpObj = key;    key = Right ().key;    Right ().key = tmpObj;    Right ().AdjustHeight ();    AdjustHeight ();}