### Question:
SingleProviderResolver { public static <T> T resolve(Class<T> c) { return resolve(c, null); }  static T resolveMandatory(Class<T> c); static T resolve(Class<T> c); @SuppressWarnings("unchecked") static synchronized T resolve(Class<T> c, Class<? extends T> defaultImpl);  }### Answer:
@Test public void testUnknown() { assertNull(SingleProviderResolver.resolve(Unknown.class)); }