### Question:
TreeWalker { public static void walkTree(GraphDatabaseService db, boolean inclProParte, StartEndHandler ... handler) { walkTree(db, inclProParte, null, null, null, handler); }  static void walkTree(GraphDatabaseService db, boolean inclProParte, StartEndHandler ... handler); static void walkTree(GraphDatabaseService db, boolean inclProParte, @Nullable Node root, @Nullable Rank lowestRank, @Nullable Meter meter, StartEndHandler ... handler); static void walkAcceptedTree(GraphDatabaseService db, StartEndHandler ... handler); static void walkAcceptedTree(GraphDatabaseService db, @Nullable Node root, @Nullable Rank lowestRank, @Nullable Meter meter, StartEndHandler ... handler);  }### Answer:
@Test public void testWalkTree() throws Exception { StringWriter writer = new StringWriter(); TreeWalker.walkTree(db, true, new TxtPrinter(writer)); System.out.println(writer.toString()); assertEquals(Resources.toString(Resources.getResource("traverse/tree.txt"), Charsets.UTF_8), writer.toString()); writer = new StringWriter(); TreeWalker.walkTree(db, true, phylum, null, null, new TxtPrinter(writer)); assertEquals(Resources.toString(Resources.getResource("traverse/treePhylum.txt"), Charsets.UTF_8), writer.toString()); writer = new StringWriter(); TreeWalker.walkTree(db, true, genus, null, null, new TxtPrinter(writer)); assertEquals(Resources.toString(Resources.getResource("traverse/treeGenus.txt"), Charsets.UTF_8), writer.toString()); writer = new StringWriter(); TreeWalker.walkTree(db, true, bas, null, null, new TxtPrinter(writer)); assertEquals(Resources.toString(Resources.getResource("traverse/treeBasionym.txt"), Charsets.UTF_8), writer.toString()); writer = new StringWriter(); TreeWalker.walkTree(db, true, phylum, Rank.ORDER, null, new TxtPrinter(writer)); assertEquals(Resources.toString(Resources.getResource("traverse/tree-order.txt"), Charsets.UTF_8), writer.toString()); }