We use a expandable basemap gallery such as in this sample-code: https://developers.arcgis.com/javascript/latest/sample-code/widgets-expand/
Instead of the default-icon, we would like to use a custom image as the expandIconClass. But I don't manage to include it. I managed to include another esri-icon by using the following code-snippet.
const bgExpand = new Expand({
view: view,
content: basemapGallery,
expandIconClass: "esri-icon-collection"
});
What do I need to change, to substitute "esri-icon-collection" with a custom image, like this: https://static.arcgis.com/images/Symbols/Shapes/BlackStarLargeB.png?
