human
Here's a good function header given the following:
I wrote the below code

    def _compile():
        if isinstance(regex, str):
            return re.compile(regex, flags)
        else:
            assert (not flags), 'flags    must    be    empty    if    regex    is    passed    pre-compiled'
            return regex
    return SimpleLazyObject(_compile)

What's a good function header?
assistant
#Here's a good function header.

def _lazy_re_compile(regex, flags=0):