Midkey metadata in root index block would always be ignored by BlockIndexReader.readMultiLevelIndexRoot

public void readMultiLevelIndexRoot(HFileBlock blk, final int numEntries) throws IOException {
      DataInputStream in = readRootIndex(blk, numEntries);
      // after reading the root index the checksum bytes have to
      // be subtracted to know if the mid key exists.
      int checkSumBytes = blk.totalChecksumBytes();
      if ((in.available() - checkSumBytes) < MID_KEY_METADATA_SIZE) {
        // No mid-key metadata available.
        return;
      }
      midLeafBlockOffset = in.readLong();
      midLeafBlockOnDiskSize = in.readInt();
      midKeyEntry = in.readInt();
 }