C B L （ C o n v + B N + L e a k y R e l u ） CBL（Conv+BN+LeakyRelu） CBL（Conv+BN+LeakyRelu）
def conv2d(filter_in, filter_out, kernel_size, stride=1):
pad = (kernel_size - 1) // 2 if kernel_size else 0
return nn.Sequential(OrderedDict([
("conv", nn.Conv2d(filter_in, filter_out, kernel_size=kernel_size, stride=stride, padding=pad, bias=False)),
("bn", nn.BatchNorm2d(filter_out)),
("relu", nn.LeakyReLU(0.1)),
]))