*/
    if (throwable instanceof Error) {
      /*
       * TODO(cpovirk): Do we really want to log this if we called setException(throwable) and it
       * returned true? This was intentional (CL 46470009), but it seems odd compared to how we
       * normally handle Error.
       *
       * Similarly, do we really want to log the same Error more than once?
       */
      log(throwable);
    }
  }

     * about when we have an Object[] vs. a Comparable[] or other array type in internalArray? If we
     * used Object[], we might be able to optimize toArray() to use clone() sometimes. (See
     * cl/592273615 and cl/592273683.)
     */
    public Builder(Comparator<? super E> comparator) {
      this.comparator = checkNotNull(comparator);
    }

    Builder(Comparator<? super E> comparator, int expectedKeys) {