'Return dict, the formatting options.'

def _get_fmt(self, output_format, **fmt_dict):

    output_format = get_output_format(output_format)
    try:
        fmt = self.output_formats[output_format].copy()
    except KeyError:
        raise ValueError(('Unknown    format:    %s' % output_format))
    fmt.update(fmt_dict)
    return fmt
