var WFSTSerializer = new ol.format.WFS();
        var featObject =
        WFSTSerializer.writeTransaction(this.getFeatures, null, null,
        {
        featureType: 'admin_kel_batu',
        featureNS: 'http://sigweb_cafe',
        srsName: 'EPSG:4326'
        });
        var serializer = new XMLSerializer();
        var featString = serializer.serializeToString(featObject);
        var request = new XMLHttpRequest();
        request.open('POST',
       'http://127.0.0.1:8080/geoserver/sigweb_cafe/ows?SERVICE=WFS');
        request.setRequestHeader('Content-Type', 'text/xml');
        request.send(featString);
    }
});