def as_list(self):
        "return some attributes as a list"
        netloc = ''
        if self.vpath_connector:
            netloc = '(('+self.vpath_connector+'))'
        elif self.authority:
            netloc = self.authority
        else:
            netloc = self.netloc
        return [
            self.scheme,
            netloc,
            self.path,
            self.query,
            '',
            ]
return some attributes as a list