class_docstr: Provides early stopping functionality. Keeps track of an early stop criteria,
  and if it doesn't improve over time restores last best performing
  parameters.
code: def is_activated(self):
      return self.activated
  
file_path: mmf/mmf/utils/early_stopping.py
imports: import numpy
  import torch
  from mmf.utils.distributed import is_main, is_xla
label_desc: Use image node_id 3 for calling the EarlyStopping obj's underlying member method code with example usage: obj.is_activated() and returns: self