code: def forward(self, x):
      x = self.dense_1(x)
      x = self.activation(x)
      x = self.dense_2(x)
      x = self.dropout(x)
      return x
  
file_path: colossalai/tests/test_legacy/test_pipeline/test_pipelinable.py
imports: import pytest
  import torch
  from colossalai.legacy.pipeline.pipelinable import PipelinableContext
  from colossalai.testing import rerun_if_address_is_in_use, spawn
label_desc: Use image node_id 2 for calling the MLP obj's underlying member method code with example usage: obj.forward(x) and returns: x