### Question:
CommonUtil { public static String convertToString(List<String> list) { StringBuilder _sb = new StringBuilder(); for (String item : list) { if (item != null) { _sb.append(item.toLowerCase().trim()); } _sb.append("-"); } int _length = _sb.length(); if (_length > 0) { _sb.delete(_length - 1, _length); } return _sb.toString(); } private  CommonUtil(); static boolean isEmpty(List list); static boolean isBlank(String str); static String sanitize(String v); static String DateToDayString(Date date); static Date dayToDate(String day); static String convertToString(List<String> list); static Map convertToMap(Object object); static List<String> removeStringFromItems(List<String> list, String toRemove); static Integer determinePriceCatForCPM(double price); static Integer determinePriceCatForCPC(double price); static Integer determinePriceCatForCPD(double price); static Integer determinePriceCatForCPT(double price); static Integer determinePriceCat(double price, TargetingChannel.PriceModel priceModel); static String removeEscapingCharacters(String str); static boolean equalNumbers(double d1, double d2);  }### Answer:
@Test public void convertToString() { List list = new ArrayList(); assertEquals("", CommonUtil.convertToString(list)); list.add("abc"); list.add("qowrqpwd"); assertEquals("abc-qowrqpwd", CommonUtil.convertToString(list)); }