code: def add_child(self, node):
      assert isinstance(node, StatNode)
  
      if self.find_child_index(node.name) == -1:  # not exist
          self.children.append(node)
  
imports: import queue
label_desc: Use image node_id 24 for calling the StatNode obj's underlying member method code with example usage: obj.add_child(node) without return types