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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def save_model(proto, f, format=None):  # type: (Union[ModelProto, bytes], Union[IO[bytes], Text], Optional[Any]) -> None
    '''
    Saves the ModelProto to the specified path.

    @params
    proto should be a in-memory ModelProto
    f can be a file-like object (has "write" function) or a string containing a file name
    format is for future use
    '''
    if isinstance(proto, bytes):
        proto = _deserialize(proto, ModelProto())

    model_filepath = _get_file_path(f)
    if model_filepath:
        basepath = os.path.dirname(model_filepath)
        proto = write_external_data_tensors(proto, basepath)

    s = _serialize(proto)
    _save_bytes(s, f)