### Question:
DummyTransformResolver extends TransformResolver { @Override public Object resolve(Object contextObject, String name, ResolutionContext context) { if (contextObject == null && matches(name)) { return marker; } else if (contextObject != null && contextObject.equals(marker)) { return performTransformation(contextObject, name, context); } return null; } DummyTransformResolver(int priority,
            String... matchNames);  DummyTransformResolver(int priority,
            Transformer transformer, String... matchNames); @Override Object resolve(Object contextObject, String name,
            ResolutionContext context);  }### Answer:
@Test public void testResolution() { MustacheEngineBuilder.newBuilder() .omitServiceLoaderConfigurationExtensions() .addResolver(resolver).build(); assertNull(resolver.resolve(null, "whatever", null)); Object marker = resolver.resolve(null, "ng", null); assertNotNull(marker); assertEquals("{{FOO}}", resolver.resolve(marker, "foo", null)); }