### Question:
StringUtil { public static boolean containsIgnoreCase(String[] array, String value) { for (String str : array) { if (value == null && str == null) { return true; } if (value != null && value.equalsIgnoreCase(str)) { return true; } } return false; }  static boolean containsIgnoreCase(String[] array, String value); static String join(String[] array, String separator); static String join(Collection<String> list, String separator);  }### Answer:
@Test public void testContainsIgnoreCase() { assertTrue(StringUtil.containsIgnoreCase(new String[]{"abc"}, "abc")); assertTrue(StringUtil.containsIgnoreCase(new String[]{"abc"}, "ABC")); assertTrue(StringUtil.containsIgnoreCase(new String[]{"ABC"}, "abc")); assertTrue(StringUtil.containsIgnoreCase(new String[]{null, "abc"}, "ABC")); assertTrue(StringUtil.containsIgnoreCase(new String[]{null, "abc"}, null)); assertFalse(StringUtil.containsIgnoreCase(new String[]{"abc"}, "def")); assertFalse(StringUtil.containsIgnoreCase(new String[]{}, "ABC")); assertFalse(StringUtil.containsIgnoreCase(new String[]{}, null)); }