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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 _check_copy_number_changes(svtype, cn, minor_cn, data):
 """Check if copy number changes match the expected svtype. """

    if svtype == "LOH" and minor_cn == 0:
        return svtype
    elif svtype == "amplification" and cn > dd.get_ploidy(data):
        return svtype
    else:
        return "std"