'Format result with formatting function
:param format_func: Func for formating result.'

@classmethod
def _gen_res(cls, format_func):

    result = ''
    for res in cls.result:
        if isinstance(res, dict):
            result += (format_func(res) + '\n')
        else:
            result += (str(res[0]) + '\n')
    return result
