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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _pb_timestamp_to_datetime(timestamp_pb):
 """Convert a Timestamp protobuf to a datetime object. :type timestamp_pb: :class:`google.protobuf.timestamp_pb2.Timestamp` :param timestamp_pb: A Google returned timestamp protobuf. :rtype: :class:`datetime.datetime` :returns: A UTC datetime object converted from a protobuf timestamp. """

    return _EPOCH + datetime.timedelta(
        seconds=timestamp_pb.seconds, microseconds=(timestamp_pb.nanos / 1000.0)
    )