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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def merge(bedfiles):
 """ given a BED file or list of BED files merge them an return a bedtools object """

    if isinstance(bedfiles, list):
        catted = concat(bedfiles)
    else:
        catted = concat([bedfiles])
    if catted:
        return concat(bedfiles).sort().merge()
    else:
        return catted