code: def test_build_preset_model(self):
      configs = [
          {"name": "resnet18", "use_se": True},
          {
              "name": "resnet50",
              "heads": [
                  {
                      "name": "fully_connected",
                      "unique_id": "default_head",
                      "num_classes": 1000,
                      "fork_block": "block3-2",
                      "in_plane": 2048,
                  }
              ],
          },
          {
              "name": "resnext50_32x4d",
              "heads": [
                  {
                      "name": "fully_connected",
                      "unique_id": "default_head",
                      "num_classes": 1000,
                      "fork_block": "block3-2",
                      "in_plane": 2048,
                  }
              ],
          },
      ]
      for config in configs:
          model = build_model(config)
          self.assertIsInstance(model, ResNeXt)
  
imports: import collections
  import unittest
  import torch
  import torchvision.models
  from classy_vision.generic.util import get_torch_version
  from classy_vision.models import build_model, ResNeXt
  from test.generic.utils import compare_model_state
label_desc: Use image node_id 3 for calling the TestResnext obj's underlying member method code with example usage: obj.test_build_preset_model() without return types