assertTrue(SessionSetupHandler.class.isAssignableFrom(impl.getClass()), "Type should be assignable");
    }

    @Test
    @DisplayName("Edge: null is not an instance of the interface")
    void testNullIsNotInstance() {
        // Assert
        assertFalse(SessionSetupHandler.class.isInstance(null));
    }

    @Test
    @DisplayName("Invalid: looking up constructor on interface fails")