* Callers of TestContainerGenerator.order need to be prepared for implementations to return a new
     * collection.
     */
    @SuppressWarnings("CanIgnoreReturnValueSuggester")
    @Override
    public List<String> order(List<String> insertionOrder) {
      sort(insertionOrder, Collections.reverseOrder());
      return insertionOrder;
    }
  }

   * Anyway, the purpose of this method is to implement a BinaryOperator combiner for a Collector,
   * so its return value will get used naturally.
   */
  @SuppressWarnings("CanIgnoreReturnValueSuggester")
  TopKSelector<T> combine(TopKSelector<T> other) {
    for (int i = 0; i < other.bufferSize; i++) {
      this.offer(uncheckedCastNullableTToT(other.buffer[i]));
    }
    return this;
  }