### Question:
StringUtils { public static boolean isEmpty(final String text) { return text == null || text.length() == 0; }  static boolean isEmpty(final String text); static boolean isNotEmpty(final String text); static boolean isBlank(final String text); static boolean isNotBlank(final String text); static int length(final String text); static String[] split(final String str, final String separatorChars); static String lowerWord(CharSequence cs, char c); static int asciiSizeInBytes(long v); static String join(String... strings); static String build(String delimiter, String prefix, String suffix, String... strings); static byte[] utf8Bytes(CharSequence str); static byte[] bytes(CharSequence str); static byte[] bytes(CharSequence str, Charset charset); static String format(String str, Object... arguments); static String readString(InputStream inputStream); static String readString(InputStream inputStream, Charset charset); static String readString(Reader reader); static final String EMPTY; static final String SPACE; static final String LF; static final String CR; static final String COMMA; static final String[] EMPTY_STRING_ARRAY; }### Answer:
@Test public void testIsEmpty() { assertTrue(StringUtils.isEmpty("")); assertTrue(StringUtils.isEmpty(null)); assertTrue(!StringUtils.isEmpty(" ")); assertTrue(!StringUtils.isEmpty("test")); assertTrue(!StringUtils.isEmpty(" test ")); }