In the 3.* API, I can turn on clustering and by default, "If you set a renderer with a colorInfo visual variable on a layer, for example, and enable clustering, then the clusters will average the numeric value driving the color visualization and shade the clusters based on the average value."
Can I customize the symbology of the clusters so that they are more visually distinct from the unclustered features? For example, since clusters tend to be pretty big symbols, it would be nice if I could make the middle of the symbol transparent and let the user see the basemap underneath.
