code: def get_existing_al_ids(self):
      existing_al_files = self.opt.get("existing_al_files")
      if existing_al_files is None:
          return {}
      existing_al_ids = {}
      for existing in existing_al_files:
          with open(existing) as f:
              data = json.load(f)
          for datatype, blob in data.items():
              if datatype not in existing_al_ids:
                  existing_al_ids[datatype] = []
              for dialog_id in blob:
                  existing_al_ids[datatype].append(dialog_id)
      return existing_al_ids
  
imports: from parlai.core.params import ParlaiParser
  from parlai.core.script import ParlaiScript, register_script
  from parlai.tasks.google_sgd_simulation_splits.agents import GoogleSgdOutDomainParser
  from parlai.core.tod.tod_agents import TodStructuredDataParser
  import parlai
  import os
  import json
  import random
label_desc: Use image node_id 6 for calling the GetAlSamplesForGsgdScript obj's underlying member method code with example usage: obj.get_existing_al_ids() and returns: existing_al_ids, dict