code: @SuppressWarnings("unchecked")
  	public static Object getRng(Object subject, int index)
  	{
  		if (subject instanceof VDMMap)
  		{
  			VDMMap map = (VDMMap) subject;
  
  			VDMSeq seq = SeqUtil.seq();
  			seq.addAll(map.values());
  
  			return seq.get(index);
  		}
  
  		throw new IllegalArgumentException("Method is only supported for "
  				+ VDMMap.class);
  	}
docs: /* @ helper @