### Question:
StrKit { public static boolean isNotEmpty(String str) { return false == isEmpty(str); }  static String firstCharToLowerCase(String str); static String firstCharToUpperCase(String str); static boolean isEmpty(String str); static boolean isNotEmpty(String str); static String nullToEmpty(String str); static String nullToDefault(String str, String defaultStr); static String toUnderlineCase(String camelCaseStr); static String toCamelCase(String name); static final String SPACE; static final String DOT; static final String SLASH; static final String BACKSLASH; static final String EMPTY; static final String CRLF; static final String NEWLINE; static final String UNDERLINE; static final String COMMA; static final String HTML_NBSP; static final String HTML_AMP; static final String HTML_QUOTE; static final String HTML_LT; static final String HTML_GT; static final String EMPTY_JSON; }### Answer:
@Test public void testIsNotEmpty() { Assert.assertTrue(StrKit.isNotEmpty(",")); Assert.assertFalse(StrKit.isNotEmpty(null)); }