code: def forward(self, x):
      x = self.layer_1(x)
      x = self.layer_2(x)
      x = self.layer_3(x)
      return x
  
file_path: pytorch-lightning/tests/tests_pytorch/utilities/test_parameter_tying.py
imports: import pytest
  import torch
  from lightning.pytorch.demos.boring_classes import BoringModel
  from lightning.pytorch.utilities import find_shared_parameters, set_shared_parameters
  from torch import nn
label_desc: Use image node_id 2 for calling the ParameterSharingModule obj's underlying member method code with example usage: obj.forward(x) and returns: x