// If this part returns false, there are definitely no runs of size >= maxRunBeforeFallback.
        int testBlockSize = maxRunBeforeFallback / 2;
        for (int i = endOfStartRun + 1; i + testBlockSize <= startOfEndRun; i += testBlockSize) {
          boolean runGood = false;
          for (int j = 0; j < testBlockSize; j++) {
            if (hashTable[i + j] == null) {
              runGood = true;
              break;