code: def __init__(self, expanders):
      self._selected_expander = expanders["selected"]
      self.expander_pool = {}
      for expander in expanders["options"]:
          if expander["type"] == "maskedlm":
              self.expander_pool[expander["value"]] = MLMExpander(
                  model_path=expander["value"]
              )
  
imports: from neuralqa.expander import MLMExpander
  import logging
label_desc: Use image node_id 1 to create a new ExpanderPool object  with example: obj = ExpanderPool(expanders)