Should `rowData` be merged with `mcols(gr)`?

[LiNk-NY]

Hi Hervé, @hpages I have an example here:

library(GenomicRanges)
library(SummarizedExperiment)
example(GRanges)
example(SummarizedExperiment)
ss <- se[1:10, ]
rowData(ss)
rowRanges(ss) <- gr
rowData(ss)
## equivalently
mcols(ss) 

Shouldn't rowData(ss) be a combination of the previous object's rowData and the mcols of the merged GRanges, i.e., DataFrame(rowData(ss), mcols(gr))?

Thank you, Marcel