public static void stall_till_cloudsize(String[] args, int x) {
   if (!_stall_called_before) {
     H2O.main(args);
     H2O.registerRestApis(System.getProperty("user.dir"));
     _stall_called_before = true;
   }
   H2O.waitForCloudSize(x, 30000);
   _initial_keycnt = H2O.store_size();
 }
 /** Starts H20 server in local mode */
 public static void startH2O(String port) {
   if (!isH2OServerStarted) {
     String[] args = new String[2];
     args[0] = "-port";
     args[1] = port;
     H2OApp.main(args);
     H2O.waitForCloudSize(1, 10 * 1000 /* ms */);
     isH2OServerStarted = true;
     log.info("H2o Server has started.");
   } else {
     log.warn("H2O Server is already Running.");
   }
 }