add default options as {}

src/layers/LayerBaseVectorGeoJson.ts

@@ -53,7 +53,7 @@ export class LayerBaseVectorGeoJson extends LayerBaseVector {
      * @param {mapMoveMakeGetParams} [options.mapMoveMakeGetParams=function(lyr, extent, zoomLevel){}] function to create additional map move params
      * @param {MapMoveCls} [options.mapMoveObj=mapMove] alternate map move object for use with multi map pages
      */
-    constructor(url, options?: LayerBaseVectorGeoJsonOptions) {
+    constructor(url, options: LayerBaseVectorGeoJsonOptions = {}) {
         url = typeof url == 'string' ? url : '';
         super(url, options);
 

src/layers/LayerBaseXyzTile.ts

@@ -32,7 +32,7 @@ export class LayerBaseXyzTile extends LayerBase {
      * @param {boolean} [options.legendContent] additional content to add to the legend
      * @param {boolean} [options.useEsriStyle=false] if the map service style should be used
      */
-    constructor(url: string, options: LayerBaseOptions) {
+    constructor(url: string, options: LayerBaseOptions = {}) {
         super(url, options);
         this._source = new ol.source.XYZ({url: this.url == '' ? undefined : this.url});
 

src/layers/LayerEsriTile.ts

@@ -38,7 +38,7 @@ export class LayerEsriTile extends LayerBaseXyzTile {
      * @param {boolean} [options.legendContent] additional content to add to the legend
      * @param {boolean} [options.useEsriStyle=false] if the map service style should be used
      */
-    constructor(url: string, options: LayerEsriTileOptions) {
+    constructor(url: string, options: LayerEsriTileOptions = {}) {
         if (url.search(/\/$/) == -1) {
             url += '/';
         }