code: protected List<String> searchResultToRobotUrlStrings(String resultHost, String scheme) {
  		ArrayList<String> list = new ArrayList<String>();
  		
  		if (resultHost.startsWith("www")) {
  			if (resultHost.startsWith("www.")) {
  				list.add(hostToRobotUrlString(resultHost, scheme));
  				list.add(hostToRobotUrlString(resultHost.substring(4), scheme));
  			} else {
  				Matcher m = WWWN_PATTERN.matcher(resultHost);
  				if(m.find()) {
  					String massagedHost = resultHost.substring(m.end());
  					list.add(hostToRobotUrlString("www." + massagedHost, scheme));
  					list.add(hostToRobotUrlString(massagedHost, scheme));
  				}
  				list.add(hostToRobotUrlString(resultHost, scheme));
  			}
  		} else {
  			list.add(hostToRobotUrlString(resultHost, scheme));			
  			list.add(hostToRobotUrlString("www." + resultHost, scheme));
  		}
  		
  		return list;
  	}
docs: (from RedisRobotExclusionFilter)