public synchronized OrderedResultsExecutor<MapTileTask> getMapRenderingExecutor() {
   if (mapRenderingExecutor == null && globalParallelFetches > 1) {
     mapRenderingExecutor =
         new OrderedResultsExecutor<MapTileTask>(globalParallelFetches, "tilesReader");
     mapRenderingExecutor.start();
   }
   return mapRenderingExecutor;
 }
 /** Stop all the threads and stuff used for this config. */
 public synchronized void close() {
   try {
     WMSServerInfo.clearCache();
   } finally {
     try {
       if (mapRenderingExecutor != null) {
         mapRenderingExecutor.stop();
       }
     } finally {
       if (connectionManager != null) {
         connectionManager.shutdown();
       }
     }
   }
 }