code: public boolean isLinux() {
  		if(!isLinuxDone) {
  			String agent = req.getHeader("user-agent");
  			isLinux=agent == null || agent.toLowerCase(Locale.ROOT).contains("linux");
  			isLinuxDone=true;
  		}
  		return isLinux;
  	}
docs: Determines if the request is for a Linux browser