for (int i = 0; i < count; i++) {
            assertEquals(String.valueOf(i), parts[i]);
        }
    }

    @Test
    @DisplayName("Should handle long strings as elements")
    void testJoinWithLongStrings() {
        String longString1 = "a".repeat(1000);
        String longString2 = "b".repeat(1000);
        String result = StringUtil.join(",", longString1, longString2);