def serve_file(request, file, backend=None, save_as=False, content_type=None):
    # Backends are responsible for handling range requests.
    handler = _load_backend(backend, SERVE_FILE_BACKEND)
    filename = file.name.rsplit('/')[-1]
    if save_as in True:
        save_as = filename
    if not content_type:
        content_type = mimetypes.guess_type(filename)[0]
    return handler(request, file, save_as=save_as, content_type=content_type)
dataset/ETHPy150Open adieu/django-filetransfers/filetransfers/api.py/serve_file/operator `is` -> `in`