class_docstr: This Teacher is responsible for performing the task of Dialogue State Tracking.
  
  It can be used to evaluate LM on JGA (Joint Goal Accuracy) metric (as shown in
  [SimpleTOD](https://arxiv.org/abs/2005.00796) and
  [Soloist](https://arxiv.org/abs/2005.05298)).
class_docstr_tok: ["This","Teacher","is","responsible","for","performing","the","task","of","Dialogue","State","Tracking",".","It","can","be","used","to","evaluate","LM","on","JGA","(","Joint","Goal","Accuracy",")","metric","(","as","shown","in","[","SimpleTOD","]","(","https",":","\/\/arxiv.org\/abs\/2005.00796",")","and","[","Soloist","]","(","https",":","\/\/arxiv.org\/abs\/2005.05298",")",")","."]
code: def _get_curr_belief_states(self, turn):
      belief_states = []
      for frame in turn["frames"]:
          if "state" in frame:
              if "slot_values" in frame["state"]:
                  for domain_slot_type in frame["state"]["slot_values"]:
                      for slot_value in frame["state"]["slot_values"][
                          domain_slot_type
                      ]:
                          domain, slot_type = domain_slot_type.split(
                              "-"
                          )
                          belief_state = f"{domain} {slot_type} {slot_value.lower()}"
                          belief_states.append(belief_state)
      return sorted(list(set(belief_states)))
  
imports: import copy
  import json
  import os
  from typing import Optional
  import numpy
  import pandas
  import parlai.core.tod.tod_agents
  import parlai.core.tod.tod_core
  import parlai.tasks.multiwoz_v22.build
  from parlai.core.message import Message
  from parlai.core.metrics import AverageMetric
  from parlai.core.opt import Opt
  from parlai.core.params import ParlaiParser
  from parlai.utils.data import DatatypeHelper
  from parlai.utils.io import PathManager
  from parlai.utils.testing import is_this_circleci
label_desc: Use image node_id 3 for calling the MultiWOZv22DSTTeacher obj's underlying member method code with example usage: obj._get_curr_belief_states(turn) and returns: sorted