docs: public static Map<String, Object> putAllIfNew(Map<String, Object> dest, Map<String, Object> source)
      {
      	if (dest == null)
      		return source;
      	if (source == null)
      	    return dest;
      	for (String key : source.keySet())
      	{
      		if (dest.get(key) == null)
      			dest.put(key, source.get(key));
      	}
      	return dest;
      }