code: def forward(self, input):
      out = self.container(input)
  
      # Make sure it's at the right level of the stack
      assert len(self._external_params) == 0
      assert len(self.container._external_params) == 1
      assert len(self.container.dangler._external_params) == 0
      return out
  
imports: from types import SimpleNamespace
  import torch
  import pytest
  import deepspeed
  from deepspeed.runtime.zero.partition_parameters import ZeroParamStatus
  from utils import setup_serial_env
  from unit.common import DistributedTest
label_desc: Use image node_id 2 for calling the DanglingExt obj's underlying member method code with example usage: obj.forward(input) and returns: out