How to use the extract-goal-features.py ?

[Sky-railway]

Thanks for your great work ,I want to reproduce the work and re-train the model.but I do not know what does the 'chunk_index' mean in the extract-goal-features.py? what value should I give to the 'chunk_index' when run the extract-goal-features.py file. As follows: parser.add_argument( "--chunk_index", required=True, type=int, help="the chunk index", )