/*
   * We are currently considering the elements in buffer in the range [0, bufferSize) as candidates
   * for the top k elements. Whenever the buffer is filled, we quickselect the top k elements to the
   * range [0, k) and ignore the remaining elements.
   */
  private final @Nullable T[] buffer;
  private int bufferSize;

  /**
   * The largest of the lowest k elements we've seen so far relative to this comparator. If

              protected List<String> create(String[] elements) {
                return new AbstractList<String>() {
                  @Override
                  public int size() {
                    return elements.length;
                  }

                  @Override
                  public String get(int index) {
                    return elements[index];
                  }
                };