_0 = conv3x3(in_channels,out_channels,kernel_size=1,stride=1,padding=0)
self.downsample = downsample...:
residual = self.downsample(x)
else:
residual = self.downsample_0(x)...= 1):
downsample = nn.Sequential(
conv3x3(in_channels, out_channels,..._0): Conv2d(256, 512, kernel_size=(1, 1), stride=(1, 1), bias=False)
(downsample): Sequential(
(0..._0): Conv2d(512, 1024, kernel_size=(1, 1), stride=(1, 1), bias=False)
(downsample): Sequential(
(