code: public boolean shouldStopBefore(InternalKey internalKey)
      {
          // Scan to find earliest grandparent file that contains key.
          InternalKeyComparator internalKeyComparator = inputVersion.getInternalKeyComparator();
          while (grandparentIndex < grandparents.size() && internalKeyComparator.compare(internalKey, grandparents.get(grandparentIndex).getLargest()) > 0) {
              if (seenKey) {
                  overlappedBytes += grandparents.get(grandparentIndex).getFileSize();
              }
              grandparentIndex++;
          }
          seenKey = true;
  
          if (overlappedBytes > MAX_GRAND_PARENT_OVERLAP_BYTES) {
              // Too much overlap for current output; start new output
              overlappedBytes = 0;
              return true;
          }
          else {
              return false;
          }
      }
docs: before processing "internal_key".