class_docstr: Checks that saved data is correct with a single batch.
code: def _test_max_turn_helper(self, max_turns):
      config = {}
      config["batchsize"] = 1
      config["max_turns"] = max_turns
      config[test_agents.TEST_NUM_ROUNDS_OPT_KEY] = 10
      config[test_agents.TEST_NUM_EPISODES_OPT_KEY] = 5  # cause why not
      agents, opt = self.setup_agents(config)
      script = TestTodWorldScript(opt)
      script.agents = agents
      script.run()
  
      def filter_round_utt(utts):
          # tad imprecise, but more important that it does stop.
          # subtract 1 for the context turn, then 1 cause there's an off by one somewhere
          return utts[: max_turns - 2]
  
      self._check_correctness_from_script_logs(
          script, opt, filter_round_utt
      )
  
imports: import copy
  import unittest
  import parlai.core.tod.tod_test_utils.test_agents
  import parlai.core.tod.tod_core
  import parlai.scripts.tod_world_script
  from parlai.core.tod.tod_agents import StandaloneApiAgent
label_desc: Use image node_id 4 for calling the TodWorldSingleBatchTest obj's underlying member method code with example usage: obj._test_max_turn_helper(max_turns) and returns: utts