code: protected Set<L> filterMotionListeners(Set<MotionListener> motionListeners) {
  		
  		Set<L> filteredMotionListeners = new HashSet<L>();
  		
  		for (MotionListener motionListener : motionListeners) {
  			
  			if(motionListenerClass.isAssignableFrom(motionListener.getClass()))
  				filteredMotionListeners.add(motionListenerClass.cast(motionListener));
  		}
  		
  		return filteredMotionListeners;
  	}
docs: <p>Takes a {@link Set} of {@link MotionListener}s and filter out those that are of the type
  handled by this implementation of {@link AbstractMotionEventResolver}.
  
  @param motionListeners
  the {@link Set} of {@link MotionListener}s which are to be filtered
  
  @return	the filtered {@link Set} of {@link MotionListener}s
  
  @since 1.0.0