code: def _parse_value(cls, stream_rdr, offset, value_count, value_offset):
          
          if value_count == 1:
              numerator = stream_rdr.read_long(value_offset)
              denominator = stream_rdr.read_long(value_offset, 4)
              return numerator / denominator
          else:  # pragma: no cover
              return 'Multi-value Rational NOT IMPLEMENTED'
docs: Return the rational (numerator / denominator) value at *value_offset*
          in *stream_rdr* as a floating-point number. Only supports single
          values at present.