buildUrl:function( path ,params ){
        let url = "" + path;
        let _paramUrl = "";
        if(  params ){
            _paramUrl = Object.keys( params ).map( function( k ){
                return [ encodeURIComponent( k ),encodeURIComponent( params[ k ] ) ].join("=");
            }).join("&");
            _paramUrl = "?" + _paramUrl;
        }
        return url + _paramUrl;
    }