docs: public synchronized void waitForLevel() {
          while (!levelReached) {
              if (hookSet == false) {
                  Runtime.getRuntime().addShutdownHook(shutdownHook);
                  hookSet = true;
              }
  
              try {
                  wait();
              } catch (InterruptedException e) {
                  /** No-op **/
              }
          }
      }