docs: private int bucketIndexFor(final int value) {
      if (value < cutoff) {
        return value / interval;
      }
      int bucket = num_linear_buckets  // Skip all linear buckets.
        // And find which bucket the rest (after `cutoff') should be in.
        // Reminder: the first exponential bucket ends at 2^exp_bucket_shift.
        + log2rounddown((value - cutoff) >> exp_bucket_shift);
      if (bucket >= buckets.length) {
        return buckets.length - 1;
      }
      return bucket;
    }