    @Test
    void similar() {

        // must result in the same ID
        String id1 = Id.build("foo_bar");
        String id2 = Id.build("foo-bar");
        String id3 = Id.build("foo bar");
        assertEquals(id1, id2);
        assertEquals(id1, id3);
        assertEquals(id2, id3);

        // must result in the same ID
        String id4 = Id.build("foobar");
        String id5 = Id.build("fooBar");
        assertEquals(id4, id5);

        // must not be the same
        assertNotEquals(id1, id4);
    }