code: def LocaltimeToUTC(cls, timestamp, timezone, is_dst=False):
      
      if timezone and timezone != pytz.UTC:
        datetime_object = (
            datetime.datetime(1970, 1, 1, 0, 0, 0, 0, tzinfo=None) +
            datetime.timedelta(microseconds=timestamp))
  
        # Check if timezone is UTC since utcoffset() does not support is_dst
        # for UTC and will raise.
        datetime_delta = timezone.utcoffset(datetime_object, is_dst=is_dst)
        seconds_delta = int(datetime_delta.total_seconds())
        timestamp -= seconds_delta * definitions.MICROSECONDS_PER_SECOND
  
      return timestamp
docs: Converts the timestamp in localtime of the timezone to UTC.
  
      Args:
        timestamp: The timestamp which is an integer containing the number
                   of micro seconds since January 1, 1970, 00:00:00 UTC.
        timezone: The timezone (pytz.timezone) object.
        is_dst: A boolean to indicate the timestamp is corrected for daylight
                savings time (DST) only used for the DST transition period.
  
      Returns:
        The timestamp which is an integer containing the number of micro seconds
        since January 1, 1970, 00:00:00 UTC or 0 on error.