### Question:
StringTool { public static String toFirstLower(String string) { return string.replaceFirst("\\w", Character.toString(string.toLowerCase().charAt(0))); } private  StringTool(); static String toFirstLower(String string); static String toFirstUpper(String string); static String fillStringRight(String s, char fillChar, int size); static String fillStringLeft(String s, char fillChar, int size); static String truncRight(String s, int size); static String truncLeft(String s, int size); static String fillString(char fillChar, int count); static String deleteAccent(String s); static boolean equalsIgnoreCaseAndAccents(String s1, String s2); static boolean isDigital(String s); static String extractStringFromRight(String string, int startIndex, int lenght); static String getHexString(byte[] bytes); static String capitalizeFirstLetter(String s); static List<Integer> getIntegerList(String string); static String getIdListString(Collection<? extends Model> collection); static String getFilename(String name); static String cutTooLongString(String str);  }### Answer:
@Test public void testToFirstLower() { String actual = "Test"; String result = "test"; Assert.assertEquals(StringTool.toFirstLower(actual), result); }