code: def test_resnest_stem():
      # Test default stem_channels
      model = ResNet(50)
      assert model.stem_channels == 64
      assert model.conv1.out_channels == 64
      assert model.norm1.num_features == 64
  
      # Test default stem_channels, with base_channels=3
      model = ResNet(50, base_channels=3)
      assert model.stem_channels == 3
      assert model.conv1.out_channels == 3
      assert model.norm1.num_features == 3
      assert model.layer1[0].conv1.in_channels == 3
  
      # Test stem_channels=3
      model = ResNet(50, stem_channels=3)
      assert model.stem_channels == 3
      assert model.conv1.out_channels == 3
      assert model.norm1.num_features == 3
      assert model.layer1[0].conv1.in_channels == 3
  
      # Test stem_channels=3, with base_channels=2
      model = ResNet(50, stem_channels=3, base_channels=2)
      assert model.stem_channels == 3
      assert model.conv1.out_channels == 3
      assert model.norm1.num_features == 3
      assert model.layer1[0].conv1.in_channels == 3
  
      # Test V1d stem_channels
      model = ResNetV1d(depth=50, stem_channels=6)
      model.train()
      assert model.stem[0].out_channels == 3
      assert model.stem[1].num_features == 3
      assert model.stem[3].out_channels == 3
      assert model.stem[4].num_features == 3
      assert model.stem[6].out_channels == 6
      assert model.stem[7].num_features == 6
      assert model.layer1[0].conv1.in_channels == 6
  
file_path: mmdetection/tests/test_models/test_backbones/test_resnet.py
imports: import pytest
  import torch
  from mmcv.ops import DeformConv2dPack
  from torch.nn.modules import AvgPool2d, GroupNorm
  from torch.nn.modules.batchnorm import _BatchNorm
  from mmdet.models.backbones import ResNet, ResNetV1d
  from mmdet.models.backbones.resnet import BasicBlock, Bottleneck
  from mmdet.models.layers import ResLayer, SimplifiedBasicBlock
  from .utils import check_norm_state, is_block, is_norm
label_desc: Use image node_id 6 for calling a global function with example usage: test_resnest_stem() without return types