message: set parent in the verification function
diff: @@ -643,6 +643,7 @@ void BPlusTreeInner::verify() const
  }
  else {
  BPlusTreeInner node(m_tree);
  + node.set_parent(const_cast<BPlusTreeInner*>(this), i + 1);
  node.init_from_mem(mem);
  node.verify();
  elems_in_child = node.get_tree_size();
  