Why do two definitions of struct PyramidLayerInfo exist?

[derselbst]

I was trying to use ISingleChannelPyramidLayerTileAccessor::Get(), which needs a PyramidLayerInfo struct. I didn't pay much attention to where this struct is actually defined. So I just took one instance obtained by CCZIReader::GetPyramidStatistics() and wanted to pass it to the accessor. To my surprise, it didn't compile, because the struct PyramidLayerInfo is defined in two places, leading to the error:

cannot convert from 'libCZI::PyramidStatistics::PyramidLayerInfo' to 'libCZI::ISingleChannelPyramidLayerTileAccessor::PyramidLayerInfo'

Ofc, I could just manually convert it. But I do wonder if there is a reason why there are two definitions of the very same PyramidLayerInfo struct? Would you consider removing one of the definitions?