Generate the final CSS string

def create_css(self, fileid=None):
        """
        Generate the final CSS string
        """
        if fileid:
            rules = self._rules.get(fileid) or []
        else:
            rules = self.rules

        compress = self._scss_opts.get('compress', True)
        if compress:
            sc, sp, tb, nl = False, '', '', ''
        else:
            sc, sp, tb, nl = True, ' ', '  ', '\n'

        scope = set()
        return self._create_css(rules, scope, sc, sp, tb, nl, not compress and self._scss_opts.get('debug_info', False))