code: public MethodlessRouter<T> addRoute(String pathPattern, T target) {
  		PathPattern p = new PathPattern(pathPattern);
  		if (routes.containsKey(p)) {
  			return this;
  		}
  
  		routes.put(p, target);
  		return this;
  	}
docs: This method does nothing if the path pattern has already been added.
  A path pattern can only point to one target.