操作Storage，包含cookie、sessionStorage、localStorage。 category值SESSION对应sessionStorage，LOCAL对应localStorage，COOKIE对应cookie
set(key, value, category = SESSION, expired)
往Storage中存入一个值
get(key, category = SESSION)
从Storage中取得值
clear(category = SESSION)
清除所有值
remove(key, category = SESSION)
删除key对应的值