### Question:
ActGraph implements Graph { @Override public String toString() { return StringFactory.graphString(this, ""); } private  ActGraph(ObjectManager objectManager, FactManager factManager, Predicate<FactEntity> hasFactAccess); @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(); boolean hasFactAccess(FactEntity fact); ObjectManager getObjectManager(); FactManager getFactManager(); static Builder builder();  }### Answer:
@Test public void testStandardStringRepresentation() { assertTrue(getActGraph().toString().matches(".*\\[.*\\]")); }