code: public static boolean isInjMap(Object subject)
  	{
  		if (subject instanceof VDMMap)
  		{
  			VDMMap map = (VDMMap) subject;
  			@SuppressWarnings("unchecked")
  			HashSet<Object> values = new HashSet<>(map.values());
  
  			return map.keySet().size() == values.size();
  		} else
  		{
  			return false;
  		}
  	}
docs: /* @ helper @