[Caffe2] codes related to normalization

Hi developers of pytorch. I am trying to figure out some caffe codes related to normalization. When I read normalize_op.h, I see some codes like

ConstStridedVec xVec(xData + base, 1, m, InnerStride(sf));
StridedVec yVec(yData + base, 1, m, InnerStride(sf));

I am not sure what ConstStridedVec or StridedVec do and I can hardly find some information about them. Could you please enlight me what they do? Please let me know if here is not a right place to ask questions about Caffe2.