src/transformers/file_utils.py/requires_backends
def requires_backends(obj, backends):
    if not isinstance(backends, (list, tuple)):
        backends = [backends]

    name = obj.__name__ if hasattr(obj, "__name__") else obj.__class__.__name__
    if not all(BACKENDS_MAPPING[backend][0]() for backend in backends):
        raise ImportError("".join([BACKENDS_MAPPING[backend][1].format(name) for backend in backends]))