public static Set<String> splitToSet(String value, char separatorChar) {
        return splitToSet(value, separatorChar, false);
    }
@Test
    void testSplitToSet() {
        String value = "1# 2#3 #4#3";
        Set<String> values = splitToSet(value, '#', false);
        assertEquals(ofSet("1", " 2", "3 ", "4", "3"), values);

        values = splitToSet(value, '#', true);
        assertEquals(ofSet("1", "2", "3", "4"), values);
    }