code: public static IntsRef deepCopyOf(IntsRef other) {
          return new IntsRef(Arrays.copyOfRange(other.ints, other.offset, other.offset + other.length), 0, other.length);
      }
docs: Creates a new IntsRef that points to a copy of the ints from
  <code>other</code>
  <p>
  The returned IntsRef will have a length of other.length
  and an offset of zero.