code: def _hashing_map(binary_record):
    
    proto = kv_pb.KeyValue()
    proto.ParseFromString(binary_record)
    yield (proto.key(), proto.value())
docs: A map function used in hash phase.
  
    Reads KeyValue from binary record.
  
    Args:
      binary_record: The binary record.
  
    Yields:
      The (key, value).