ObjectManager - A class for adding a large number of objects to the map
without needing to create placemarks and add them to the map individually.
The objects added to the ObjectManager are located in the ObjectManager.objects collection. Clusters formed from the
added placemarks are added to the ObjectManager.clusters collection.
The visual representation of placemarks is created asynchronously on demand. The visual representation of placemarks and clusters are objects implementing the IOverlay interface. In particular, overlay.Placemark.
Overlays are placed in the ObjectManager.objects.overlays and ObjectManager.clusters.overlays collections, respectively.
ObjectManageraccepts placemark descriptions in JSON format. Placemarks can be clustered or shown as-is.
If you don't use clusterization, the placemarks will be shown only in the visible map area.
Since objects are stored in the manager as JSON descriptions and their visual representation is created only when necessary,
this method of adding points to the map works faster than adding placemarks to the map directly or via the clusterer.