code: def save_config(self, fname, output_dir, cp=None):
          
          cp = self.cp if cp is None else cp
          ini_file_path = os.path.join(output_dir, fname)
          with open(ini_file_path, "wb") as fp:
              cp.write(fp)
          ini_file = FileList([File(self.ifos, "",
                                    self.analysis_time,
                                    file_url="file://" + ini_file_path)])
          return ini_file
docs: Writes configuration file to disk and returns a pycbc.workflow.File
          instance for the configuration file.
  
          Parameters
          -----------
          fname : string
              The filename of the configuration file written to disk.
          output_dir : string
              The directory where the file is written to disk.
          cp : ConfigParser object
              The ConfigParser object to write. If None then uses self.cp.
  
          Returns
          -------
          FileList
              The FileList object with the configuration file.