code: def save_model(self, file_name='model.cx'):
          
          with open(file_name, 'wt') as fh:
              cx_str = self.print_cx()
              fh.write(cx_str)
docs: Save the assembled CX network in a file.
  
          Parameters
          ----------
          file_name : Optional[str]
              The name of the file to save the CX network to. Default: model.cx