code: @SuppressWarnings("ObjectEquality")
      @Override
      public int compareTo(Slice that)
      {
          if (this == that) {
              return 0;
          }
          return compareTo(0, size, that, 0, that.size);
      }
docs: Compares the content of the specified buffer to the content of this
  buffer.  This comparison is performed byte by byte using an unsigned
  comparison.