Return sequences for the exon pairs
addSeq(exonPairs, src)
| exonPairs | a list of GRanges with the splice junction exon pairs. For a single pair a single GRanges object may be provided.  | 
    
|---|---|
| src | whether a BSgenome instance, e.g. BSgenome.Hsapiens.NCBI.GRCh38, XStringSet object or a FaFile object  | 
    
a list of GRanges with additional `seq` data column with the retrieved sequence.