code: def test_model(self):
      dummy_img = torch.rand(1, 3, 4, 4)
      model = vit.create_model(
          num_classes=400, img_size=4, patch_size=2
      )
      features = model.forward_features(dummy_img)
      self.assertTrue(features.shape, (1, 768))
      out = model(dummy_img)
      self.assertEqual(out.shape, (1, 400))
  
file_path: towhee/tests/unittests/models/vit/test_vit.py
imports: import unittest
  import os
  import json
  import torch
  from tests.unittests import VIT_DIR
  from torchvision import transforms
  from towhee.utils.pil_utils import PILImage
  from towhee.models import vit
label_desc: Use image node_id 2 for calling the VisionTransformerTest obj's underlying member method code with example usage: obj.test_model() without return types