BinarySearchTree { public static boolean checkBST(TreeNode<Integer> root){ return checkBSTMinMax(root, Integer.MIN_VALUE, Integer.MAX_VALUE); }  static boolean checkBST(TreeNode<Integer> root);  }
@Test public void testYES(){ node8.left = node6; node8.right = node11; node6.left = node4; node6.right = node7; node4.left = node4_4; node4.right = node5; node11.left = node9; node11.right = node12; node9.left = node9_9; Assert.assertTrue(BinarySearchTree.checkBST(node8)); }