String[] result = invokeDistinct(null);
        assertNotNull(result);
        assertEquals(0, result.length);
        assertSame(StringUtil.EMPTY_STRINGS, result);
    }

    public void test_distinct_emptyArray() {
        // Test distinct with empty array
        String[] input = new String[0];
        String[] result = invokeDistinct(input);
        assertSame(input, result);
    }