code: def test_step_func_requires_iterator(self) -> None:
      class Foo:
          def bar(self, state: State, data: object) -> object:
              return data
  
          def baz(
              self, state: State, data: Iterator[torch.Tensor]
          ) -> object:
              pass
  
      def dummy(a: int, b: str, data: Iterator[str]) -> None:
          pass
  
      foo = Foo()
  
      self.assertFalse(_step_requires_iterator(foo.bar))
      self.assertTrue(_step_requires_iterator(foo.baz))
      self.assertTrue(_step_requires_iterator(dummy))
  
file_path: tnt/tests/framework/test_unit_utils.py
imports: import unittest
  from typing import Dict, Iterator
  import torch
  from torch.distributed.fsdp import FullyShardedDataParallel
  from torch.optim import Optimizer
  from torchtnt.framework._unit_utils import _find_optimizers_for_module, _step_requires_iterator
  from torchtnt.framework.state import State
  from torchtnt.utils.env import init_from_env
  from torchtnt.utils.test_utils import spawn_multi_process
label_desc: Use image node_id 1 for calling the UnitUtilsTest obj's underlying member method code with example usage: obj.test_step_func_requires_iterator() and returns: data