def serving_input_fn():
    """Dummy serving input function.

    Returns:
      dummy: A dummy tuple that looks like a ServingInputReceiver as far as
             LatestModuleExporter is concerned.

    This doesn't need to return a real ServingInputReceiver since
    LatestModuleExporter only cares that you can reconstruct the prediction
    graph using some placeholder features.
    """
    featurizer = load_featurizer(params)
    batched_structure = tf.nest.map_structure(
        lambda ph: tf.expand_dims(ph, 0),
        featurizer.query_and_docs_feature_structure)
    return collections.namedtuple("Dummy", ["features"])(batched_structure)
Dummy serving input function.

    Returns:
      dummy: A dummy tuple that looks like a ServingInputReceiver as far as
             LatestModuleExporter is concerned.

    This doesn't need to return a real ServingInputReceiver since
    LatestModuleExporter only cares that you can reconstruct the prediction
    graph using some placeholder features.
    
language/realm/model.py