@Test
 public void testOpenGraph() {
   final String graphName = "graphName";
   manager.addGraph(graphName);
   assertNotNull(managedGraphs.get(graphName));
   assertNotNull(manager.openGraph(graphName));
 }
 @Test
 public void testRemoveGraph() {
   final String graphName = "bo";
   manager.addGraph(graphName);
   manager.removeGraph(graphName);
   assertEquals(0, managedGraphs.size());
 }
 @Test
 public void testAddGraph() {
   final String graphName = "bo";
   assertEquals(0, managedGraphs.size());
   manager.addGraph(graphName);
   assertEquals(1, managedGraphs.size());
   assertNotNull(managedGraphs.get(graphName));
 }
 @Test
 public void testOpenGraphGraphManagerGraph() {
   assertNotNull(manager.openGraph(GraphManagerGraphFilterGraph.GRAPH_MANAGER_GRAPH_NAME));
 }
 @Test(expected = GraphManagementException.class)
 public void testAddGraphManagerGraph() {
   manager.addGraph(GraphManagerGraphFilterGraph.GRAPH_MANAGER_GRAPH_NAME);
 }