code: def forward(self, x):
      x_concat = torch.cat(x, dim=1)
      return self.fc(x_concat)
  
imports: import pytest
  import torch
  import torch.nn
  from torch.utils.data import DataLoader, TensorDataset
  from kale.embed.image_cnn import SimpleCNNBuilder
  from kale.pipeline.base_nn_trainer import BaseNNTrainer, CNNTransformerTrainer, MultimodalNNTrainer
  from kale.predict.class_domain_nets import ClassNet
label_desc: Use image node_id 2 for calling the _TestFusion obj's underlying member method code with example usage: obj.forward(x) and returns: self