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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 _clean_freebayes_output(line):
 """Clean FreeBayes output to make post-processing with GATK happy. XXX Not applied on recent versions which fix issues to be more compatible with bgzip output, but retained in case of need. - Remove lines from FreeBayes outputs where REF/ALT are identical: 2 22816178 . G G 0.0339196 or there are multiple duplicate alleles: 4 60594753 . TGAAA T,T - Remove Type=Int specifications which are not valid VCF and GATK chokes on. """

    if line.startswith("#"):
        line = line.replace("Type=Int,D", "Type=Integer,D")
        return line
    else:
        parts = line.split("\t")
        alleles = [x.strip() for x in parts[4].split(",")] + [parts[3].strip()]
        if len(alleles) == len(set(alleles)):
            return line
    return None