def _stringify(self, transform: StringifyTransform) -> str:
    res = [transform(self.prefix)]
    for p in self.postFixes:
        res.append(transform(p))
    return ''.join(res)
def _stringify(self, transform: StringifyTransform) -> str:
    res = [transform(self.prefix)]
    for p in self.postFixes:
        res.append(transform(p))
    return .join(res)