code: @Pure
  	public BusHub getNearestBusHub(double x, double y) {
  		double distance = Double.POSITIVE_INFINITY;
  		BusHub bestHub = null;
  		double dist;
  
  		for (final BusHub hub : this.validBusHubs) {
  			dist = hub.distance(x, y);
  			if (dist < distance) {
  				distance = dist;
  				bestHub = hub;
  			}
  		}
  
  		return bestHub;
  	}
docs: Replies the nearest bus hub to the given point.
  
  @param x x coordinate.
  @param y y coordinate.
  @return the nearest bus hub or <code>null</code> if none was found.