### Question:
StringUtil { public static StringBuilder appendRepeatedly(StringBuilder result, String str, int times) { for (int i=0; i<times; i++) result.append(str); return result; }  static boolean isEmpty(String str); static String getLeft(String src, int length); static String getRight(String src, int length); static boolean isDigitOnly(String chkStr); static String SQLEscape(String str); static String fillString(String str, int length, char fillChar, boolean fillLeft); static String cEscape(String str); static String cEscape(String str, char quoteChar); static String cEscape(String str, char quoteChar, boolean isWchar); static String lowerFirst(String str); static String upperFirst(String str); static boolean isJavaIdentifier(String str); static int[] splitAsIntArray(String str, String delimiter); static String join(byte[] items, String delimiter); static String join(String[] items, String delimiter); static String join(List<String> items, String delimiter); static StringBuilder appendRepeatedly(StringBuilder result, String str, int times); static StringBuilder appendRepeatedly(StringBuilder result, char c, int times); static String toTrimmedStr(Object o, int len);  }### Answer:
@Test public void testAppendRepeatedly() { assertEquals("123abab", StringUtil.appendRepeatedly(new StringBuilder("123"), "ab", 2).toString()); assertEquals("123 ", StringUtil.appendRepeatedly(new StringBuilder("123"), ' ', 2).toString()); }