docs: public static String printValues(String start, String separator, String end, Iterator<?> values) {
          if(start == null){
              start = "(";
          }
          if (separator == null){
              separator = ",";
          }
          if (end == null){
              end = ")";
          }
  
          StringBuilder sb = new StringBuilder(start);
          while(values.hasNext()) {
              sb.append(print(values.next()));
              if (values.hasNext()) {
                  sb.append(separator);
              }
          }
          return sb.append(end).toString();
      }