laravel Method IlluminateValidationValidator::validateReuqired does not exist.

Method IlluminateValidationValidator::validateReuqired does not exist.
此错误是由于我们在配置验证时，写错了关键字，

 public function rules()
    {
        return [
            'file'=>'required',
            'folder'=>'reqiured',    // 这里reqiured错误，应该required
        ];
    }