### Question:
JaxbAssertionBuilder implements AssertionBuilder<Element> { public QName[] getKnownElements() { return supportedTypes.toArray(new QName[0]); } JaxbAssertionBuilder(QName qn); @SuppressWarnings("unchecked")  JaxbAssertionBuilder(String className, QName qn);  JaxbAssertionBuilder(Class<T> type, QName qn); Assertion build(Element element, AssertionBuilderFactory factory); QName[] getKnownElements();  }### Answer:
@Test public void testGetKnownElements() throws Exception { QName qn = new QName("http: JaxbAssertionBuilder<FooType> ab = new JaxbAssertionBuilder<>(FooType.class, qn); assertNotNull(ab); assertEquals(1, ab.getKnownElements().length); assertSame(qn, ab.getKnownElements()[0]); }