code: public void addMapDataStore(MapDataStore mapDataStore, boolean useStartZoomLevel, boolean useStartPosition) {
          if (this.mapDatabases.contains(mapDataStore)) {
              throw new IllegalArgumentException("Duplicate map database");
          }
          this.mapDatabases.add(mapDataStore);
          if (useStartZoomLevel) {
              this.startZoomLevel = mapDataStore.startZoomLevel();
          }
          if (useStartPosition) {
              this.startPosition = mapDataStore.startPosition();
          }
          if (null == this.boundingBox) {
              this.boundingBox = mapDataStore.boundingBox();
          } else {
              this.boundingBox = this.boundingBox.extendBoundingBox(mapDataStore.boundingBox());
          }
      }
docs: adds another mapDataStore
  
  @param mapDataStore      the mapDataStore to add
  @param useStartZoomLevel if true, use the start zoom level of this mapDataStore as the start zoom level
  @param useStartPosition  if true, use the start position of this mapDataStore as the start position