But in here 89 someone said that it is just a reshape function:
class scale_to_depth(nn.Module):
    def __init__(self, block_size=1):
        super(scale_to_depth, self).__init__()
        self.block_size = block_size        
    def forward(self, input):
        inputSize = input.size()
        batch = inputSize[0]
        channel = inputSize[1]
        height = inputSize[2]
        width = inputSize[3]
        return input.view(-1, channel * self.block_size * self.block_size,
                      int(height/self.block_size), int(width/self.block_size))

Here is my implementation!