code: def _register_json_primitive(object_type, encoder, decoder):
    
    global _TYPE_TO_ENCODER
    global _TYPE_NAME_TO_DECODER
    if object_type not in _TYPE_TO_ENCODER:
      _TYPE_TO_ENCODER[object_type] = encoder
      _TYPE_NAME_TO_DECODER[object_type.__name__] = decoder
docs: Extend what Pipeline can serialize.
  
    Args:
      object_type: type of the object.
      encoder: a function that takes in an object and returns
        a dict of json primitives.
      decoder: inverse function of encoder.