DataCubeCanvasService.subscribeSelectionChanged Method
        
 Subscribe/Unsubscribe an event handler to the selection changed event.
 
         
        Parameters
        
            - callback
            
 
            - 
                
Type: Function
The callback method to subscribe or unsubscribe. 
            - unsubscribe
            
 
            - 
                
Type: Boolean
True if unsubscribe should happen instead.