code: def forward(self, x) -> torch.Tensor:
      linear: nn.Module = getattr(self, self.linear_name)
      out: torch.Tensor = linear(x)
  
      if self.is_last_rank:
          out = out.sum()
      return out
  
imports: import argparse
  import os
  import warnings
  import torch
  import torch.distributed.rpc
  import torch.multiprocessing
  from torch import nn
  from torch._C._distributed_rpc import _is_current_rpc_agent_set
  from colossalai.legacy import launch
  from colossalai.legacy.pipeline.pipeline_process_group import ppg
  from colossalai.logging import disable_existing_loggers
label_desc: Use image node_id 2 for calling the RpcTestModel obj's underlying member method code with example usage: obj.forward(x) and returns: out