src/transformers/models/marian/convert_marian_to_pytorch.py/find_model_file
def find_model_file(dest_dir):  # this one better
    model_files = list(Path(dest_dir).glob("*.npz"))
    if len(model_files) != 1:
        raise ValueError(f"Found more than one model file: {model_files}")
    model_file = model_files[0]
    return model_file