Thanks Robert Scheitlin, GISP but this highlightEnabled property seems not to work for me. Despite that you gave me some inspiration to solve the problem by using the following properties on my mapview.
view = new MapView({
map: webmap,
container: "viewDiv",
highlightOptions: {
color: [255,255,255,0]
}
});
I've achieved, what I wanted, despite that I'd like to know how you'd have solved this problem with the property you mentioned.