### Question:
Rank { public void add (Node node) { this.nodes.add (node); } Rank(String name, RankType type); void add(Node node);  }### Answer:
@Test public void testAdd () { Rank rank = new Rank ("rankName", RankType.SAME); Node node = new Node ("nodeName"); rank.add (node); assertTrue (rank.nodes.contains (node)); }