### Question:
StringUtil { public static boolean equalsIgnoreCase(final CharSequence str1, final CharSequence str2) { if (str1 == null || str2 == null) { return str1 == str2; } else if (str1 == str2) { return true; } else if (str1.length() != str2.length()) { return false; } else { return regionMatches(str1, true, 0, str2, 0, str1.length()); } }  static boolean equalsIgnoreCase(final CharSequence str1, final CharSequence str2); static boolean equals(String str1, String str2); static boolean isBlank(String str); static boolean isNotBlank(String str); static boolean isEmpty(String str); static boolean isNotEmpty(String str); static String trimToEmpty(String str); static String trim(String str); static String capitalize(String str); static final String EMPTY; }### Answer:
@Test public void testEqualsIgnoreCase() { Assert.assertFalse(StringUtil.equalsIgnoreCase("", "BCCC")); Assert.assertFalse(StringUtil.equalsIgnoreCase(null, "")); Assert.assertTrue(StringUtil.equalsIgnoreCase("", "")); Assert.assertTrue(StringUtil.equalsIgnoreCase("BcCc", "BCCC")); Assert.assertTrue(StringUtil.equalsIgnoreCase(null, null)); }