function writeFeatureToEsriJSON(feature, sourceCode, targetCode) {
    try {
        var view = map.getView();
        if (!feature) {
            return null;
        }
        var format = new ol.format.EsriJSON();
        var esriJson = format.writeFeatureObject(feature, {
            featureProjection: targetCode || view.getProjection(),
            dataProjection: sourceCode || view.getProjection(),
        });
    return esriJson;
} catch (e) {
    return null;
}
}