I can get the results of liftOver when I run the commond in linux shell:

                        "liftOver input.bed hg38ToMm10.over.chain.gz out.bed unmap.bed"

My question is how can I get the unmap.bed(such as '#Partially deleted in new \ #Split in new \ #Deleted in new') when I use R-package liftOver(version:1.12.0)?

I have confirm that the '#Delete in new' will return a null GRanges and '#Split in new' will return a GRanges with two seqnames when I run liftOVer in R. What about '#Partially deleted in new'?

How can I recognize the '#Partially deleted in new' in R ?