code: protected static void checkQueues(final Iterable<String> queues) {
          if (queues == null) {
              throw new IllegalArgumentException("queues must not be null");
          }
          for (final String queue : queues) {
              if (queue == null || "".equals(queue)) {
                  throw new IllegalArgumentException("queues' members must not be null: " + queues);
              }
          }
      }
docs: Verify that the given queues are all valid.
  
  @param queues the given queues