I am using the run_mlm.py provided in the transformers repository to pretrain bert. The dataset is of version 1.8.0. Since the used dataset Wikipedia is large, I hope the processing is one time and can be reused later. However, I find it always re-computing instead of load from the disk. I don’t think I changed any parameters to the map function. I notice the description of the parameter  new_fingerprint might influence. The original codes of run_mlm.py do not specify it, should I give it a value?