You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: systemSetting.go
    path of file: ./repos/sun-panel/service/lib/cmn/systemSetting
    
    the code of the file until where you have to start completion: package systemSetting

import (
	"encoding/json"
	"errors"
	"sun-panel/lib/cache"
	"sun-panel/models"

	"gorm.io/gorm"
)

const (
	SYSTEM_APPLICATION    = "system_application"
	SYSTEM_EMAIL          = "system_email"
	DISCLAIMER            = "disclaimer"            // 免责声明 储存类型：字符串
	WEB_ABOUT_DE
    
func (s *SystemSettingCache) GetValueByInterface(configName string, value interface{}) error {
	if v, ok := s.Cache.Get(configName); ok {
		// fmt.Println("缓存")
		if s, sok := v.(string); sok {
			if err := json.Unmarshal([]byte(s), value); err != nil {
				return err
			}
			return nil
		}
	}

	mSetting := models.SystemSetting{}
	result, err := mSetting.Get(configName)
	if err == gorm.ErrRecordNotFound {
		err = ErrorNoExists
		return err
	}
	err = json.Unmarshal([]byte(result), value)
	if err != nil {
		return err
	}
	s.Cache.SetDefault(configName, result)
	return nil
}