When using the marker_cluster example, I cannot hide all the underlying markers at once as with other layers by setting a `visible` trait to `False`: ``` from ipyleaflet import Map, Marker, MarkerCluster m = Map(center=(50, 0), zoom=5) marker1 = Marker(location=(48, -2)) marker2 = Marker(location=(50, 0)) marker3 = Marker(location=(52, 2)) marker_cluster = MarkerCluster( markers=(marker1, marker2, marker3) ) m.add_layer(marker_cluster); marker_cluster..visible = False m ``` In order to do it I can only hide each underlying marker individually. Would it it be a desirable feature ?