code: def test_validation_step(multimodal_model):
      x = [torch.rand(1, 5) for _ in range(2)]
      y = torch.tensor([1])
      batch = [*x, y]
      multimodal_model.validation_step(batch, 0)
  
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 7 for calling a global function with example usage: test_validation_step(multimodal_model) without return types