Variables not defined for generator test?

Course Q&A TensorFlow Developer Professional Convolutional Neural Networks in TensorFlow
1

The code for train_val_generators function passes when run. But the test function returns the below error, which looks like the parameters for the test are not defined?

---------------------------------------------------------------------------

NameError                                 Traceback (most recent call last)

<ipython-input-2-372236d1ff86> in <module>
      1 # Test your generators
----> 2 train_generator, validation_generator = train_val_generators(TRAINING_DIR, VALIDATION_DIR)

NameError: name 'TRAINING_DIR' is not defined
2

You should check again, maybe somehow the kernel timed out and you might need to run that cell again. Otherwise the error is straight forward!