Loads external tensors into model

    @params
    model: ModelProto to load external data to
    base_dir: directory that contains external data

def load_external_data_for_model(model, base_dir):  # type: (ModelProto, Text) -> None
    """
    Loads external tensors into model

    @params
    model: ModelProto to load external data to
    base_dir: directory that contains external data
    """
    for tensor in _get_all_tensors(model):
        if uses_external_data(tensor):
            load_external_data_for_tensor(tensor, base_dir)