code: public void registerMap(String applicationId, String mapId, Map map) {
  		HashMap<String, Map> mapMap;
  		if (maps.containsKey(applicationId)) {
  			mapMap = maps.get(applicationId);
  			if (!mapMap.containsKey(mapId)) {
  				mapMap.put(mapId, map);
  			}
  		} else {
  			mapMap = new HashMap<String, Map>();
  			mapMap.put(mapId, map);
  			maps.put(applicationId, mapMap);
  		}
  	}
docs: Register the given {@link Map} with applicationId and mapId.
  
  @param applicationId
  the application id.
  @param mapId
  the map id.
  @param map
  the map to register.