code: def forward(self, x: torch.Tensor) -> torch.Tensor:
      return self.ffn(x).sum(-1)
  
imports: import torch
  import torch.nn
  import pytest
  from allennlp.common.params import Params
  from allennlp.common.testing import multi_device
  from allennlp.nn.checkpoint.checkpoint_wrapper import CheckpointWrapper, TorchCheckpointWrapper
label_desc: Use image node_id 2 for calling the BasicModule obj's underlying member method code with example usage: obj.forward(x) and returns: self