code: def test_content(self):
      data = [0] * 8
  
      # set up engine
      def _train_func(engine, batch):
          pass
  
      engine = Engine(_train_func)
  
      # set up testing handler
      val_data_loader = torch.utils.data.DataLoader(Dataset(data))
      evaluator = TestEvaluator(torch.device("cpu:0"), val_data_loader)
      ValidationHandler(
          interval=2, validator=evaluator, exec_at_start=True
      ).attach(engine)
      # test execution at start
      engine.run(data, max_epochs=1)
      self.assertEqual(evaluator.state.max_epochs, 1)
      self.assertEqual(evaluator.state.epoch_length, 8)
      self.assertEqual(evaluator.state.output, "called")
  
      engine.run(data, max_epochs=5)
      self.assertEqual(evaluator.state.max_epochs, 4)
      self.assertEqual(evaluator.state.epoch_length, 8)
  
file_path: MONAI/tests/test_handler_validation.py
imports: from __future__ import annotations
  import unittest
  import torch
  from ignite.engine import Engine
  from monai.data import Dataset
  from monai.engines import Evaluator
  from monai.handlers import ValidationHandler
label_desc: Use image node_id 1 for calling the TestHandlerValidation obj's underlying member method code with example usage: obj.test_content() without return types