Unknown command line flag 'data_format'

I got the following bug. Could you please help? Thank you!

$python main.py --network_header_type=nips --env_name=Breakout-v0 --use_gpu=False
Traceback (most recent call last):
File "main.py", line 173, in
tf.app.run()
File "/Documents/openai_gym/openai_gym/lib/python3.6/site-packages/tensorflow/python/platform/app.py", line 126, in run
_sys.exit(main(argv))
File "main.py", line 107, in main
conf.data_format = 'NHWC'
File "/Documents/openai_gym/openai_gym/lib/python3.6/site-packages/tensorflow/python/platform/flags.py", line 88, in __setattr__
return self.__dict__['__wrapped'].__setattr__(name, value)
File "/Documents/openai_gym/openai_gym/lib/python3.6/site-packages/absl/flags/_flagvalues.py", line 496, in __setattr__
return self._set_unknown_flag(name, value)
File "/Documents/openai_gym/openai_gym/lib/python3.6/site-packages/absl/flags/_flagvalues.py", line 374, in _set_unknown_flag
raise _exceptions.UnrecognizedFlagError(name, value)
absl.flags._exceptions.UnrecognizedFlagError: Unknown command line flag 'data_format'