@ParameterizedTest @MethodSource("testSplitArguments")
    void testSplit(String input, String separator, String... expected) {
        assertArrayEquals(expected, input.split(separator));
    }
    static Stream<Arguments> testSplitArguments() {
        return Stream.of(arguments("a/b/c",  "/", new String[] {"a", "b", "c"}),
                         arguments("abc",    "/", new String[] {"abc"}),
                         arguments("a/b/c/", "/", new String[] {"a", "b", "c"})
    );}