code: public static String repeat(String s, int count) {
        if (s == null) {
           return null;
        }
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < count; i++) {
           builder.append(s);
        }
        return builder.toString();
     }
docs: Repeat string.
  
  @param s     the s
  @param count the count
  @return the string