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.
You can filter the objects added to the ObjectManager using the setFilter method. The method sets the filter function for objects. It accepts a single object added to the ObjectManager. If the function returns true, the object will be processed. If false, the object will be excluded from further processing. You can also pass a string as the filter. The following keywords are available in the filter string: