No enclosing instance..

클래스를 static으로 해주지 않았는데 인스턴스를 생성하려할 때 발생하는 에러 메시

No enclosing instance of type Dijkstra_ShortestPath is accessible. Must qualify the allocation with an enclosing instance of type Dijkstra_ShortestPath (e.g. x.new A() where x is an instance of Dijkstra_ShortestPath).