org.jboss.resteasy.spi.UnhandledException: java.lang.RuntimeException: Unable to resolve type variable

Testcase:

public class ParameterizedSubResourceTest
{
private static Dispatcher dispatcher;

@BeforeClass
public static void before() throws Exception

{ dispatcher = EmbeddedContainer.start().getDispatcher(); dispatcher.getRegistry().addPerRequestResource(RootImpl.class); }

@AfterClass
public static void after() throws Exception

{ EmbeddedContainer.stop(); }

public static interface Root
{
@Path("sub/

{path}

")
public Sub getSub(@PathParam("path") String path);
}

public static interface Sub

{ @GET @Produces("text/plain") public String get(); }

public static interface InternalInterface<T extends Number>

{ @PUT void foo(T value); }

@Path("/path")
public static class RootImpl implements Root
{
@Override
public SubImpl<Integer> getSub(String path)

{ return new SubImpl<Integer>(path); }

}

public static class SubImpl<T extends Number> implements Sub, InternalInterface<T>
{
private final String path;

public SubImpl(String path)

{ this.path = path; }

@Override
public String get()

{ return "Boo! - " + path; }

@Override
public void foo(T value)

{ System.out.println("foo: " + value); }

}

@Test
public void test()
{
ClientRequest request = new ClientRequest(generateURL("/path/sub/fred"));
ClientResponse<String> response = null;
try

{ response = request.get(String.class); Assert.assertEquals(HttpResponseCodes.SC_OK, response.getStatus()); Assert.assertEquals("Boo! - fred", response.getEntity()); }

catch (Exception e)

{ throw new RuntimeException(e); }

}
}