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

    def match(m):
        if (m.group(1) is None):
            return (u'_' if (m.group(0) == u'\\u') else u'\\')
        try:
            return six.unichr(int(m.group(1)))
        except (ValueError, OverflowError) as _:
            return ''
    trimmed = (escaped_token[:(-1)] if escaped_token.endswith('_') else escaped_token)
    return _UNESCAPE_REGEX.sub(match, trimmed)

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

def _unescape_token(escaped_token):