### Question:
Utils { static int indexOf(CharSequence cs, CharSequence searchChar, int start) { return cs.toString().indexOf(searchChar.toString(), start); } private  Utils(); static String join(String delimiter, String wrap, Iterable<?> objs); static String join(String delimiter, Iterable<?> objs); static String concat(CharSequence... strings); static void closeQuietly(Closeable closeable); static String escape(String str, boolean escapeSingleQuote); static String unescape(String str); static String hex(char ch); static boolean isEmpty(CharSequence cs); static T notNull(T object, String message, Object... values); static void isTrue(boolean expression, String message); static void onlyOneIsTrue(final String message, final boolean... expressions); static boolean onlyOneIsTrueNonThrow(final boolean... expressions); static T notEmpty(T chars, String message, Object... values); static String toString(Object o);  }### Answer:
@Test public void testIndexOf() { Assert.assertEquals(-1, Utils.indexOf("bar", "foo", 0)); Assert.assertEquals(-1, Utils.indexOf("bar", "a", 2)); Assert.assertEquals(1, Utils.indexOf("bar", "a", 0)); Assert.assertEquals(1, Utils.indexOf("bar", "a", 1)); }