code: def save_rst(self, file_name='pysb_model.rst', module_name='pysb_module'):
          
          if self.model is not None:
              with open(file_name, 'wt') as fh:
                  fh.write('.. _%s:\n\n' % module_name)
                  fh.write('Module\n======\n\n')
                  fh.write('INDRA-assembled model\n---------------------\n\n')
                  fh.write('::\n\n')
                  model_str = pysb.export.export(self.model, 'pysb_flat')
                  model_str = '\t' + model_str.replace('\n', '\n\t')
                  fh.write(model_str)
docs: Save the assembled model as an RST file for literate modeling.
  
          Parameters
          ----------
          file_name : Optional[str]
              The name of the file to save the RST in.
              Default: pysb_model.rst
          module_name : Optional[str]
              The name of the python function defining the module.
              Default: pysb_module