@Test
void join() {

    assertNull(StringUtils.join(null, 0, 0, DELIM));
    assertEquals("", StringUtils.join(StringUtils.EMPTY_STRINGS, 0, 0, DELIM));
    assertEquals("A", StringUtils.join(ONE, 0, 1, DELIM));
    assertEquals(JOINED, StringUtils.join(ARRAY, 0, ARRAY.length, DELIM));
}