code: def _ValidateClosedTimeRange(time_range):
    
    time_range_start, time_range_end = time_range
    _ValidateTimestamp(time_range_start)
    _ValidateTimestamp(time_range_end)
    if time_range_start > time_range_end:
      raise ValueError("Invalid time-range: %d > %d." %
                       (time_range_start.AsMicrosecondsSinceEpoch(),
                        time_range_end.AsMicrosecondsSinceEpoch()))
docs: Checks that a time-range has both start and end timestamps set.