* 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;
  }