docs: public static <R> R suspendWhenNull(long intervalAsMillis,
              Supplier<R> objectSupplier) {
          R object = objectSupplier.get();
          if (object == null) {
              log.warn("Start Suspending !!!");
              long startTimeMillis = System.currentTimeMillis();
              while ((object = objectSupplier.get()) == null)
                  sleep(intervalAsMillis);
              log.warn("Stop Suspending Over {} ms",
                      System.currentTimeMillis() - startTimeMillis);
          }
          return object;
      }