code: def save_model(self, file_name=None):
          
          if file_name is None:
              logger.error('Missing file name')
              return
          pcc.model_to_owl(self.model, file_name)
docs: Save the BioPAX model object in an OWL file.
  
          Parameters
          ----------
          file_name : Optional[str]
              The name of the OWL file to save the model in.