docs: private void setMarkerBitmap() {
          for (markerType = 0; markerType < cluster.getClusterManager().markerIconBmps.size(); markerType++) {
              // Check if the number of items in this cluster is below or equal the limit of the MarkerBitMap
              if (cluster.getItems().size() <= cluster.getClusterManager()
                      .markerIconBmps.get(markerType).getItemMax()) {
                  return;
              }
          }
          // set the markerType to maximum value ==> reduce markerType by one.
          markerType--;
      }