### Question:
ActGraph implements Graph { @Override public Iterator<Vertex> vertices(Object... vertexIds) { if (SetUtils.set(vertexIds).isEmpty()) throw new GraphOperationException("V() is not supported!"); return SetUtils.set(this::resolveVertex, vertexIds).iterator(); } private  ActGraph(ObjectFactDao objectFactDao,
                   ObjectFactTypeResolver objectFactTypeResolver,
                   FactRetractionHandler factRetractionHandler,
                   TiSecurityContext securityContext,
                   TraverseParams traverseParams,
                   PropertyHelper propertyHelper); @Override Vertex addVertex(Object... keyValues); @Override C compute(Class<C> graphComputerClass); @Override GraphComputer compute(); @Override Iterator<Vertex> vertices(Object... vertexIds); @Override Iterator<Edge> edges(Object... edgeIds); @Override Transaction tx(); @Override void close(); @Override Variables variables(); @Override Configuration configuration(); @Override Features features(); @Override String toString(); ObjectFactTypeResolver getObjectFactTypeResolver(); ObjectFactDao getObjectFactDao(); FactRetractionHandler getFactRetractionHandler(); TiSecurityContext getSecurityContext(); TraverseParams getTraverseParams(); PropertyHelper getPropertyHelper(); static Builder builder();  }### Answer:
@Test(expected = GraphOperationException.class) public void testFetchingAllVerticesNotAllowed() { getActGraph().vertices(); }
@Test public void testFetchingVerticesWithId() { UUID objectID = mockObjectRecord(mockObjectType(), "someValue").getId(); Iterator<Vertex> result = getActGraph().vertices(objectID); assertEquals(objectID, result.next().id()); }
@Test public void testFetchingVerticesWithVertex() { Vertex objectVertex = createVertex(); Iterator<Vertex> result = getActGraph().vertices(objectVertex); assertEquals(objectVertex, result.next()); }
@Test(expected = NoSuchElementException.class) public void testHaveExceptionConsistencyWhenFindVertexByIdThatIsNonExistent() { getActGraph().vertices(UUID.randomUUID()); }
@Test public void testIterateVerticesWithUuidIdSupportUsingVertex() { Vertex vertex1 = createVertex(); Vertex vertex2 = getActGraph().vertices(vertex1).next(); assertEquals(vertex1.id(), vertex2.id()); }
@Test public void testIterateVerticesWithUuidIdSupportUsingDetachedVertex() { Vertex vertex1 = createVertex(); Vertex vertex2 = getActGraph().vertices(DetachedFactory.detach(vertex1, true)).next(); assertEquals(vertex1.id(), vertex2.id()); assertFalse(vertex2 instanceof DetachedVertex); }
@Test public void testIterateVerticesWithUuidIdSupportUsingReferenceVertex() { Vertex vertex1 = createVertex(); Vertex vertex2 = getActGraph().vertices(ReferenceFactory.detach(vertex1)).next(); assertEquals(vertex1.id(), vertex2.id()); assertFalse(vertex2 instanceof ReferenceVertex); }
@Test public void testIterateVerticesWithUuidIdSupportUsingVertexId() { Vertex vertex1 = createVertex(); Vertex vertex2 = getActGraph().vertices(vertex1.id()).next(); assertEquals(vertex1.id(), vertex2.id()); }
@Test public void testIterateVerticesWithUuidIdSupportUsingVertices() { Vertex vertex1 = createVertex(); Vertex vertex2 = createVertex(); assertEquals(2, IteratorUtils.count(getActGraph().vertices(vertex1, vertex2))); }
@Test public void testIterateVerticesWithUuidIdSupportUsingVertexIds() { Vertex vertex1 = createVertex(); Vertex vertex2 = createVertex(); assertEquals(2, IteratorUtils.count(getActGraph().vertices(vertex1.id(), vertex2.id()))); }