code: def add_opt(self, opt, value=None):
          
          if value is None:
              self.common_options += [opt]
          else:
              self.common_options += [opt, value]
docs: Add option to job.
  
          Parameters
          -----------
          opt : string
              Name of option (e.g. --output-file-format)
          value : string, (default=None)
              The value for the option (no value if set to None).