code: def forward(self, x, y):
      y1, y2 = checkpoint(self.mlp1, x)
      y3 = checkpoint(self.relu, x)
  
      y4 = checkpoint(self.ckpt2, y)
      y5 = checkpoint(self.ckpt3, y, y4)
      y6 = self.linear2(y4)
      return y1 + y2 + y3 + y4 + y5 + y6
  
imports: import pytest
  import torch
  import torch.nn.functional
  from torch.utils.checkpoint import checkpoint
  import colossalai
  from colossalai.fx import ColoTracer
  from colossalai.fx.graph_module import ColoGraphModule
  from colossalai.legacy.core import global_context
  from colossalai.testing import rerun_if_address_is_in_use, spawn
label_desc: Use image node_id 4 for calling the MyModule obj's underlying member method code with example usage: obj.forward(x, y) and returns: unknown