class_docstr: The method base class for graph generation. To write a new graph generation method, create a new class
  inheriting from this class and implement the functions.
docstr: Running training for property optimization task.
docstr_tok: ["Running","training","for","property","optimization","task","."]
code: def train_prop_opt(self, *args, **kwargs):
      r"""
      Running training for property optimization task.
      """
  
      raise NotImplementedError(
          "The function train_prop_opt is not implemented!"
      )
  
label_desc: Use image node_id 3 for calling the Generator obj's underlying member method code with example usage: obj.train_prop_opt() without return types