code: def warm_users(self, threshold=1):
      users_list = []
      for user_id in self._index_store["positive"]:
          if len(self._index_store["positive"][user_id]) >= threshold:
              users_list.append(user_id)
      return users_list
  
file_path: openrec/openrec/tf1/utils/dataset.py
imports: import numpy
  import random
label_desc: Use image node_id 8 for calling the Dataset obj's underlying member method code with example usage: obj.warm_users(threshold) and returns: users_list