code: def test_embedded_constant_difference(self):
      class MyModel(Module):
          def __init__(self):
              super().__init__()
              self.iters = 0
  
          def forward(self, x):
              r = x[self.iters % 2]
              self.iters += 1
              return r
  
      x = torch.tensor([[1, 2], [3, 4]])
      self.assertVerifyExpectFail(MyModel(), x, backend)
  
file_path: pytorch/test/onnx_caffe2/test_verify.py
imports: import caffe2.python.onnx.backend
  import torch
  from torch.autograd import Function
  from torch.nn import Module, Parameter
  from torch.testing._internal import common_utils
  from verify import verify
label_desc: Use image node_id 5 for calling the TestVerify obj's underlying member method code with example usage: obj.test_embedded_constant_difference() and returns: r