docs: def remove_core_element(self, model):
          """Remove respective core element of handed data flow model
  
          :param DataFlowModel model: Data Flow model which core element should be removed
          :return:
          """
          assert model.data_flow.parent is self.model.state or model.data_flow.parent is self.model.parent.state
          gui_helper_state_machine.delete_core_element_of_model(model)