// Clustering
ClusterManager<ClusterItem> clusterManager = // Initialize ClusterManager - if you're using multiple maps features, use the constructor that passes in Manager objects (see next section)
clusterManager.setOnClusterItemClickListener(item -> {
    // Listen for clicks on a cluster item here
    return false;
});
clusterManager.setOnClusterClickListener(item -> {
    // Listen for clicks on a cluster here
    return false;
});

// GeoJson
GeoJsonLayer geoJsonLayer = // Initialize GeoJsonLayer - if you're using multiple maps features, use the constructor that passes in Manager objects (see next section)
geoJsonLayer.setOnFeatureClickListener(feature -> {
    // Listen for clicks on GeoJson features here
});

// KML
KmlLayer kmlLayer = // Initialize KmlLayer - if you're using multiple maps features, use the constructor that passes in Manager objects (see next section)
kmlLayer.setOnFeatureClickListener(feature -> {
    // Listen for clicks on KML features here
});

GroundOverlayManager groundOverlayManager = // Initialize 

// Create a new collection first
GroundOverlayManager.Collection groundOverlayCollection = groundOverlayManager.newCollection();

// Add a new ground overlay
GroundOverlayOptions options = // ...
groundOverlayCollection.addGroundOverlay(options);

GroundOverlayOptions options = // ...
googleMap.addGroundOverlay(options);

CustomInfoWindowAdapter adapter = // ...
OnInfoWindowClickListener listener = // ...

// Create a new Collection from a MarkerManager
MarkerManager markerManager = // ...
MarkerManager.Collection collection = markerManager.newCollection();

// Set InfoWindowAdapter and OnInfoWindowClickListener
collection.setInfoWindowAdapter(adapter);
collection.setOnInfoWindowClickListener(listener);

// Alternatively, if you are using clustering
ClusterManager<ClusterItem> clusterManager = // ...
MarkerManager.Collection markerCollection = clusterManager.getMarkerCollection();
markerCollection.setInfoWindowAdapter(adapter);
markerCollection.setOnInfoWindowClickListener(listener);

CustomInfoWindowAdapter adapter = // ...
OnInfoWindowClickListener listener = // ...
googleMap.setInfoWindowAdapter(adapter);
googleMap.setOnInfoWindowClickListener(listener);

// Create a new Collection from a MarkerManager
MarkerManager markerManager = // ...
MarkerManager.Collection collection = markerManager.newCollection();

// Add markers to collection
MarkerOptions markerOptions = // ...
collection.addMarker(markerOptions);
// ...

// Set OnMarkerDragListener
GoogleMap.OnMarkerDragListener listener = // ...
collection.setOnMarkerDragListener(listener);

// Alternatively, if you are using clustering
ClusterManager<ClusterItem> clusterManager = // ...
MarkerManager.Collection markerCollection = clusterManager.getMarkerCollection();
markerCollection.setOnMarkerDragListener(listener);

// Add markers
MarkerOptions markerOptions = // ...
googleMap.addMarker(makerOptions);

// Add listener
GoogleMap.OnMarkerDragListener listener = // ...
googleMap.setOnMarkerDragListener(listener);

clusterManager.clearItems();
clusterManager.addItems(items);
clusterManager.cluster();

private class PersonRenderer extends DefaultClusterRenderer<Person> {
        ...     
        @Override
        protected void onBeforeClusterItemRendered(Person person, MarkerOptions markerOptions) {
            // Draw a single person - show their profile photo and set the info window to show their name
            markerOptions
                    .icon(getItemIcon(person))
                    .title(person.name);
        }
        
        /**
         * New in v1 
         */
        @Override
        protected void onClusterItemUpdated(Person person, Marker marker) {
            // Same implementation as onBeforeClusterItemRendered() (to update cached markers)
            marker.setIcon(getItemIcon(person));
            marker.setTitle(person.name);
        }
        
        @Override
        protected void onBeforeClusterRendered(Cluster<Person> cluster, MarkerOptions markerOptions) {
            // Draw multiple people.
            // Note: this method runs on the UI thread. Don't spend too much time in here (like in this example).
            markerOptions.icon(getClusterIcon(cluster));
        }
       
        /**
         * New in v1 
         */
        @Override
        protected void onClusterUpdated(Cluster<Person> cluster, Marker marker) {
            // Same implementation as onBeforeClusterRendered() (to update cached markers)
            marker.setIcon(getClusterIcon(cluster));
        }
        ...
    }

private class PersonRenderer extends DefaultClusterRenderer<Person> {
        ...       
        @Override
        protected void onBeforeClusterItemRendered(Person person, MarkerOptions markerOptions) {
            // Draw a single person - show their profile photo and set the info window to show their name
            markerOptions
                    .icon(getItemIcon(person))
                    .title(person.name);
        }
        
        @Override
        protected void onBeforeClusterRendered(Cluster<Person> cluster, MarkerOptions markerOptions) {
            // Draw multiple people.
            // Note: this method runs on the UI thread. Don't spend too much time in here (like in this example).
            markerOptions.icon(getClusterIcon(cluster));
        }
        ...
    }