code: def test_efficientnet_backbone():
      """Test EfficientNet backbone."""
      with pytest.raises(AssertionError):
          # EfficientNet arch should be a key in EfficientNet.arch_settings
          EfficientNet(arch="c3")
  
      model = EfficientNet(arch="b0", out_indices=(0, 1, 2, 3, 4, 5, 6))
      model.train()
  
      imgs = torch.randn(2, 3, 32, 32)
      feat = model(imgs)
      assert len(feat) == 7
      assert feat[0].shape == torch.Size([2, 32, 16, 16])
      assert feat[1].shape == torch.Size([2, 16, 16, 16])
      assert feat[2].shape == torch.Size([2, 24, 8, 8])
      assert feat[3].shape == torch.Size([2, 40, 4, 4])
      assert feat[4].shape == torch.Size([2, 112, 2, 2])
      assert feat[5].shape == torch.Size([2, 320, 1, 1])
      assert feat[6].shape == torch.Size([2, 1280, 1, 1])
  
imports: import pytest
  import torch
  from mmdet.models.backbones import EfficientNet
label_desc: Use image node_id 1 for calling a global function with example usage: test_efficientnet_backbone() without return types