@Test public void testMethodSignatureForSelectorForStructures() {

    assertEquals("v@:^{TestStruct=id}", callbacks.methodSignatureForSelector("returnsVoidTakesStruct:"));
    assertEquals("v@:{ByValue=id}", callbacks.methodSignatureForSelector("returnsVoidTakesStructByValue:"));
    // TODO - better would be
        // assertEquals("v@:{TestStruct_ByValue=id}", callbacks.methodSignatureForSelector("returnsVoidTakesStructByValue:"));
    assertEquals("^{TestStruct=id}@:", callbacks.methodSignatureForSelector("returnsStructTakesVoid"));
    assertEquals("{ByValue=id}@:", callbacks.methodSignatureForSelector("returnsStructByValueTakesVoid"));
}