def METHOD_NAME(part1, part2, translators_comment, key, subkey):
    """makes a base unit (.po or XLIFF) out of a subkey of two parts"""
    # TODO: Do better
    text1 = getattr(part1, subkey)
    if text1 == "":
        return None
    text2 = getattr(part2, subkey)
    unit = xliff.xliffunit(text1)
    unit.target = text2
    if unit.target:
        unit.markfuzzy(False)
    else:
        unit.markfuzzy(True)
    unit.setid(key + "." + subkey)
    if getattr(translators_comment, subkey).strip() != "":
        unit.addnote(getattr(translators_comment, subkey), origin="developer")
    return unit