code: def test_forward_pre_hook_global_function_with_input_only(
      self,
  ) -> None:
      class TestModule(LazyModuleExtensionMixin, torch.nn.Module):
          """
          Create this unit test to make sure the old way of insert hook function is enabled,
          with the hook definition as:
              valid_input_only_hook(self, module, input)
  
          if we run the TestModule as::
  
              def input_only_hook(module, input_tuple):
                  return input_tuple[0] + 1
              m = TestModule()
              m.register_forward_pre_hook(input_only_hook)
              output = m(torch.zeros(2, 2))
              expected_output = torch.ones(2, 2)
          """
  
          def __init__(self, *args, **kwargs):
              super().__init__(*args, **kwargs)
  
          def initialize_parameters(self, input) -> None:
              return None
  
          def forward(self, input) -> torch.Tensor:
              return input
  
      def input_only_hook(
          module: torch.nn.Module, input: Tuple[torch.Tensor, ...]
      ) -> torch.Tensor:
          # input is tuple
          return input[0] + 1
  
      m = TestModule()
      m.register_forward_pre_hook(input_only_hook)
      output = m(torch.zeros(2, 2))
      self.assertTrue(torch.allclose(output, torch.ones(2, 2)))
  
file_path: torchrec/torchrec/modules/tests/test_lazy_extension.py
imports: import inspect
  import re
  import unittest
  from typing import Tuple
  import torch
  from torch.nn.modules.lazy import LazyModuleMixin
  from torchrec.modules.lazy_extension import lazy_apply, LazyModuleExtensionMixin
label_desc: Use image node_id 4 for calling the TestLazyModuleExtensionMixin obj's underlying member method code with example usage: obj.test_forward_pre_hook_global_function_with_input_only() and returns: unknown, None, input