$$ResUnit$$

class Resblock(nn.Module):
    def __init__(self, channels, hidden_channels=None):
        super(Resblock, self).__init__()

        if hidden_channels is None:
            hidden_channels = channels

        self.block = nn.Sequential(
            BasicConv(channels, hidden_channels, 1),
            BasicConv(hidden_channels, channels, 3),
        )

    def forward(self, x):
        return x + self.block(x)