In this example we use a MarkerCluster overlay to group the markers instead of a LayerGroup.
The layer is defined as any other overlay. The possible options can be found in the MarkerCluster docs
The MarkerCluster, at this moment, does not support the location change of the markers and they have to be
removed and added again to the cluster. So, as we remove & add markers when the model is changed, you can
experience a slight glitch during this operation. You can test it clicking the button below.