Data Structures, Algorithms, & Applications in Java
Chapter 15, Exercise 9

public class ModifiedBinarySearchTree extends BinarySearchTree
{
   public Object modifiedGet(Object theKey)
   {
      // pointer p starts at the root and moves through
      // the tree looking for an element with key theKey
      BinaryTreeNode p = root;
      Comparable searchKey = (Comparable) theKey;
      while (p != null)
         // examine p.element.key
         if (searchKey.compareTo(((Data) p.element).key) == 0) 
         // if correct key is found 
         {
            return ((Data) p.element).element;
         }
         else if (searchKey.compareTo(((Data) p.element).key) < 0)
         {
            p = p.leftChild;
         }
         else
         {
            p = p.rightChild;
         }

      // no matching element
      return null;
   }
}