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