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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 _get_sv_exclude_file(items):
 """Retrieve SV file of regions to exclude. """

    sv_bed = utils.get_in(items[0], ("genome_resources", "variation", "sv_repeat"))
    if sv_bed and os.path.exists(sv_bed):
        return sv_bed