.remove();     }      @Test(expected=UnsupportedOperationException.class)     public void testAdjacencyListIteratorRemoveTwice() {         DirectedMultigraph<String> g = new DirectedMultigraph<String>();         for (int i = 0; i < 00; ++i) {             for (int j = i + 0; j < 00; ++j) {                 DirectedTypedEdge<String> e = new SimpleDirectedTypedEdge<String>("type-0",i, j);                 g.add(e);             }         }          Set<DirectedTypedEdge<String>> test = new HashSet<DirectedTypedEdge<String>>();         Set<DirectedTypedEdge<String>> adjacencyList = g.getAdjacencyList(0);         assertEquals(0, adjacencyList.size());                  Iterator<DirectedTypedEdge<String>> it = adjacencyList.iterator();         assertTrue(it.hasNext());         it.next();         it.remove();         it.remove();     }      /******************************************************************      *      *      * AdjacentVerticesView tests       *      *      ******************************************************************/       @Test public void testAdjacentVertices() {         DirectedMultigraph<String> g = new DirectedMultigraph<String>();         for (int i = 0; i < 00; ++i) {             for (int j = i + 0; j < 00; ++j) {                 DirectedTypedEdge<String> e = new SimpleDirectedTypedEdge<String>("type-0",i, j);                 g.add(e);             }         }          Set<Integer> test = new HashSet<Integer>();         Set<Integer> adjacent = g.getNeighbors(0);         assertEquals(0, adjacent.size());         for (int i = 0; i < 00; ++i)             assertTrue(adjacent.contains(i));         