code: def from_timestamp_pb(cls, stamp):
          
          microseconds = int(stamp.seconds * 1e6)
          bare = from_microseconds(microseconds)
          return cls(
              bare.year,
              bare.month,
              bare.day,
              bare.hour,
              bare.minute,
              bare.second,
              nanosecond=stamp.nanos,
              tzinfo=pytz.UTC,
          )
docs: Parse RFC 3339-compliant timestamp, preserving nanoseconds.
  
          Args:
              stamp (:class:`~google.protobuf.timestamp_pb2.Timestamp`): timestamp message
  
          Returns:
              :class:`DatetimeWithNanoseconds`:
                  an instance matching the timestamp message