/* Recursively verify tree structure. */
size_t count;
int bh;

recurse_verify_tree (tree->rb_root, &okay, &count, 0, INT_MAX, &bh);
if (count != n)
  {
    printf (" Tree has %lu nodes, but should have %lu.\n",
            (unsigned long) count, (unsigned long) n);
    okay = 0;
  }
