Query the return type and argument list of the specified
        function in the specified database.

def query_args(self, name):
        """Query the return type and argument list of the specified
        function in the specified database.
        """
        sql = 'select type, id from code_items ' \
              'where kind = 22 and name = ?'
        logging.debug('%s %s', sql, (name,))
        self.cursor.execute(sql, (name,))
        func = self.cursor.fetchone()
        if func:
            sql = 'select param_number, type, name ' \
                  'from code_items where parent_id = ?'
            logging.debug('%s %s', sql, (func[1],))
            self.cursor.execute(sql, (func[1],))
            args = self.cursor.fetchall()
            ret_type = clean_ret_type(func[0])
            args = [
                (arg_number, sanitize_type(arg_type), arg_name)
                for arg_number, arg_type, arg_name in args
            ]
            return ret_type, name, args
        return None