code: def as_dict(self):
      elements = [{e.kind: e.as_dict()} for e in self.__elements]
      return {"feature-list": elements}
  
imports: import io
  import json
  import os
  from typing import Union
  from lets_plot._global_settings import get_global_bool, has_global_value, FRAGMENTS_ENABLED
label_desc: Use image node_id 3 for calling the FeatureSpecArray obj's underlying member method code with example usage: obj.as_dict() and returns: dict