ERROR: test_atari_init (__main__.AtariInitTest)

When I run 'python tests/atari_init_test.py', it shows below:

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ERROR: test_atari_init (__main__.AtariInitTest)
Tests that a DQN agent is initialized.
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Traceback (most recent call last):
File "tests/atari_init_test.py", line 47, in test_atari_init
train.main([])
File "/Users/kudou/Documents/codes/dopamine/dopamine/atari/train.py", line 128, in main
launch_experiment(create_runner, create_agent)
File "/Users/kudou/Documents/codes/dopamine/dopamine/atari/train.py", line 116, in launch_experiment
run_experiment.load_gin_configs(FLAGS.gin_files, FLAGS.gin_bindings)
File "/Users/kudou/anaconda2/envs/py36/lib/python3.6/site-packages/absl/flags/_flagvalues.py", line 488, in __getattr__
raise _exceptions.UnparsedFlagAccessError(error_message)
absl.flags._exceptions.UnparsedFlagAccessError: Trying to access flag --gin_files before flags were parsed.

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Ran 2 tests in 0.001s

FAILED (errors=1)