message: use copy.deepcopy()
diff: @@ -81,7 +81,7 @@ class Scenario:
  def copy(self):
  observer_model = None
  if self._observer_model is not None:
  - observer_model = self._observer_model.deepcopy()
  + observer_model = copy.deepcopy(self._observer_model)
  return Scenario(agent_list=copy.deepcopy(self._agent_list),
  eval_agent_ids=self._eval_agent_ids.copy(),
  map_file_name=self._map_file_name,
  