code: private boolean equivalent(int start1, int start2, int len) {
      if (start1 + len > size || start2 + len > size)
        return false;
  
      while (len-- > 0)
        if (serialized[start1++] != serialized[start2++])
          return false;
  
      return true;
    }
docs: Return <code>true</code> if two regions in {@link #serialized} are
  identical.