readIcons method
void
readIcons()
Implementation
void readIcons() async {
if (markerIcon == null) markerIcon = await getBytesFromAsset('packages/interactive_maps_marker/assets/marker.png', 100);
if (markerIconSelected == null) markerIconSelected = await getBytesFromAsset('packages/interactive_maps_marker/assets/marker_selected.png', 100);
}