@Override
  public long getLong(int index) {
    int offset = this.offset + index;
    long l = 0;
    for (int i = offset; i < offset + Bytes.SIZEOF_LONG; i++) {
      l <<= 8;
      l ^= bytes[i] & 0xFF;
    }
    return l;
  }
Returns true when {@code range} is of zero length, false otherwise.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/AbstractByteRange.java