### Question:
DirectedGraph extends AttributeSetWithDefaultNodeAttributes { public Node getNode (String name) { Node node = mNodes.get (name); if (node == null) { throw new GraphException (String.format ("node %s does not exist", name)); } return node; } DirectedGraph();  DirectedGraph(boolean concentrateEdges); void setConcentrateEdges(boolean value); boolean getConcentrateEdges(); void setRankDirection(RankDirection direction); RankDirection getRankDirection(); void setDistanceBetweenRanks(float distance); float getDistanceBetweenRanks(); void setDistanceBetweenNodes(float distance); float getDistanceBetweenNodes(); Node addNode(String name); Node addNode(String name, Cluster cluster); boolean hasNode(String name); Node getNode(String name); Node getRoot(); Iterator<Node> nodeIterator(); Edge addEdge(String sourceName, String targetName); Edge addEdge(Node source, String targetName); Edge addEdge(String sourceName, Node target); Edge addEdge(Node source, Node target); Edge addEdge(String sourceName, String targetName, String label); Edge addEdge(Node source, String targetName, String label); Edge addEdge(String sourceName, Node target, String label); Edge addEdge(Node source, Node target, String label); boolean hasEdge(Node source, Node target); Edge getEdge(Node source, Node target); Set<Edge> getEdgesFrom(Node source); Set<Edge> getEdgesTo(Node target); Set<Edge> getEdgesFromOrTo(Node node); Set<Node> getNeighbours(Node node, int distance); Cluster addCluster(String label); Cluster addCluster(String label, Cluster cluster); Cluster getCluster(String label); Rank addRank(String name, RankType type); Rank getRank(String name);  }### Answer:
@Test public void testGetNode () { try { mGraph.getNode (NODE_NAME); fail ("no exception"); } catch (GraphException ge) { } }