code: def stringify(self, value, **opts):
          
          if self._is_null(value):
              return None
          try:
              opts_ = self.opts.copy()
              opts_.update(opts)
              return self._stringify(value, **opts_)
          except Exception as e:
              if not isinstance(e, ConverterError):
                  e = ConverterError(None, exc=e)
              e.converter = self.__class__
              raise e
docs: Generate a string representation of the data.
  
          Inverse of conversion: generate a string representation of the data
          that is guaranteed to be parseable by this library.