code: def _iteration(self, engine, batchdata):
      engine.state.output = "called"
      return engine.state.output
  
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 TestEvaluator obj's underlying member method code with example usage: obj._iteration(engine, batchdata) and returns: engine