What is a quick way to convert the `cpgcano` object below to a data.frame that is BED6 format? I need to write out this BED6 format to work with tools outside R. Thanks

library(rtracklayer)
session <- browserSession()
genome(session) <- "rn6"
cpg <- session[["CpG Islands"]]
methods(class = class(cpg))
cpgcano <- keepStandardChromosomes(cpg)

Well. as.data.frame(cpgcano) give almost what I want. I bit of more adjustment will do. Consider case close.