`eSparse<-` is a generic function for setting expression counts in the Sparse slot
of an ScMaSigPro object.
eSparse(object, i = "counts") <- valueAn object of class ScMaSigPro.
The name of the assay for which to set expression counts. Default is "counts", which targets the default expression counts slot.
The new expression matrix to be set for the specified assay.
The modified ScMaSigPro object with the updated
expression data in the Sparse slot.