}

    // Invalid: null is not allowed for valueOf
    @ParameterizedTest
    @NullSource
    @DisplayName("valueOf(null) throws NullPointerException")
    void valueOfRejectsNull(String input) {
        assertThrows(NullPointerException.class, () -> RequestParam.valueOf(input));
    }

    // Sanity: Enum.valueOf(Class, String) behaves identically to RequestParam.valueOf(String)
    @Test