rsStorage(
    {
        //Single site is string, multi-site is array,the site's Synchronization URL of slave source(type String or Array)
        url:"http://othersite.com/src/otherSite/syncStorage.html",
        //Synchronization delay(type Number or Boolean),default:false
        delay:1000,
        //Whether bidirectional synchronization,default:false
        mutual:true,
        //Sync field, not set to all sync
        sync:['testA']
    },function(){
        //do something before each synchronization.
    },function(){
        //do something after each synchronization.
    }
);