class_docstr: Tests to check we handle impatience correctly upon preemption.
code: def test_impatience(self, **kwargs):
      from parlai.scripts.train_model import TrainModel, TrainLoop
  
      # shallow copy to prevent overwrites
      kwargs = kwargs.copy()
      with testing_utils.tempdir() as tmpdir:
          kwargs["model"] = "fake_report"
          kwargs["task"] = "integration_tests"
          kwargs["validation_metric"] = "loss"
          kwargs["model_file"] = os.path.join(tmpdir, "model")
          kwargs[
              "dict_file"
          ] = "zoo:unittest/transformer_generator2/model.dict"
          kwargs["log_every_n_steps"] = 1
          kwargs["validation_every_n_steps"] = 10
          kwargs["max_train_steps"] = 100
          kwargs["save_after_valid"] = True
          opt = TrainModel.setup_args().parse_kwargs(**kwargs)
  
          logs_first = []
          main_loop = TrainLoop(opt)
  
          for i, train_step_log in enumerate(main_loop.train_steps()):
              if i % 10 == 1:
                  # simulate preemption
                  # load from preempted and check variables are the same
                  preempt_loop = TrainLoop(opt)
                  # assert main_loop.impatience == preempt_loop.impatience
                  # assert main_loop.last_valid_epoch == preempt_loop.last_valid_epoch
                  # assert main_loop.best_valid == preempt_loop.best_valid
                  print(
                      i,
                      preempt_loop.impatience,
                      preempt_loop.best_valid,
                  )
                  if i == 1:
                      assert preempt_loop.impatience == 0
                      assert preempt_loop.best_valid is None
                  elif i == 11:
                      assert preempt_loop.impatience == 0
                      assert preempt_loop.best_valid == 3
                  elif i == 21:
                      assert preempt_loop.impatience == 1
                      assert preempt_loop.best_valid == 3
                  elif i == 31:
                      assert preempt_loop.impatience == 0
                      assert preempt_loop.best_valid == 2
                  else:
                      assert preempt_loop.impatience == (i - 31) // 10
                      assert preempt_loop.best_valid == 2
  
imports: import os
  import unittest
  import json
  import parlai.utils.logging
  import parlai.utils.testing
  from parlai.utils.io import PathManager
  from parlai.core.metrics import AverageMetric
  from parlai.core.worlds import create_task
  from parlai.core.opt import Opt
  from parlai.core.params import ParlaiParser
  from parlai.core.agents import register_agent, Agent
  from parlai.scripts.eval_model import get_task_world_logs
label_desc: Use image node_id 1 for calling the TestValidationImpatience obj's underlying member method code with example usage: obj.test_impatience() without return types