code: @Export
  	public Map getMap(String applicationId, String mapId) {
  		HashMap<String, Map> application = maps.get(applicationId);
  		if (null == application) {
  			return null;
  		}
  		return application.get(mapId);
  	}
docs: Return the {@link Map} that is registered with the given application and map ID.
  
  @param applicationId
  the application id.
  @param mapId
  the map id.
  @return the map.