def conv1x1(in_planes, out_planes, stride=1):
    '1x1 convolution'
    return nn.Conv2d(in_planes, out_planes, kernel_size=1, stride=stride, bias=False)
1x1 convolution
def conv1x1(in_planes, out_planes, stride=1):
    
    return nn.Conv2d(in_planes, out_planes, kernel_size=1, stride=stride, bias=False)