StringHelper { public static String defaultString(final String str) { return str == null ? BasicConstants.EMPTY_STRING : str; }  static String defaultString(final String str); static boolean equals(final String str1, final String str2); static boolean equalsIgnoreCase(final String str1, final String str2); static boolean isBlank(final String str); static boolean isNotBlank(final String str); static String[] split(final String str, final String separatorChars); static String substringAfterLast(final String str,
			final String separator); static final List<String> parseListPreferenceValue(
			String pRawValues, String separator); static String stripAccents(String input); static String replace(String text, String searchString,
			String replacement, int max);  }
@Test public void testDefaultString() { Assert.assertEquals("", StringHelper.defaultString(null)); Assert.assertEquals("", StringHelper.defaultString("")); Assert.assertEquals("bat", StringHelper.defaultString("bat")); }