def check_tf_version():
    """ Check that the Tensorflow version is up to date. If it isn't, print an error message and exit the script.
    """
    try:
        assert_tf_version()
    except AssertionError as e:
        print(e, file=sys.stderr)
        sys.exit(1)
 Check that the Tensorflow version is up to date. If it isn't, print an error message and exit the script.
    
keras_retinanet/utils/tf_version.py