code: def test_add_mul(self):
      class AddMulModule(torch.nn.Module):
          def __init__(self):
              super().__init__()
  
          def forward(self, a, x, b):
              y = torch.mm(a, x)
              z = torch.add(y, b)
              return z
  
      model = AddMulModule()
      model.eval()
  
      self.run_compare_torch(
          [(2, 2), (2, 2), (2, 2)],
          model,
          frontend=TorchFrontend.EDGEIR,
          backend=("mlprogram", "fp16"),
      )
  
imports: import pytest
  from coremltools._deps import _HAS_EXECUTORCH, _HAS_TORCH_VISION
  import torch
  import torchvision
  import torchaudio
  import torchsr
  import timm
  import transformers
  from .testing_utils import TorchBaseTest, TorchFrontend
label_desc: Use image node_id 4 for calling the TestExecutorch obj's underlying member method code with example usage: obj.test_add_mul() and returns: z