def METHOD_NAME(pf):
    """convert a properties file back to a .inc file with #defines in it"""
    # any leftover blanks will not be included at the end
    pendingblanks = []
    for unit in pf.units:
        for comment in unit.comments:
            if comment.startswith("# converted from") and "#defines" in comment:
                pass
            else:
                yield from pendingblanks
                # TODO: could convert commented # x=y back to # #define x y
                yield comment + "\n"
        if unit.isblank():
            pendingblanks.append("\n")
        else:
            definition = "#define {} {}\n".format(
                unit.name,
                unit.value.replace("\n", "\\n"),
            )
            yield from pendingblanks
            yield definition