code: public String getString(String name) {
          List<V> vals = get(name);
          if ((vals == null) || (vals.isEmpty())) {
              return null;
          }
  
          if (vals.size() == 1) {
              // simple form.
              return vals.get(0).toString();
          }
  
          // delimited form
          StringBuilder values = new StringBuilder(128);
          for (V e : vals) {
              if (e != null) {
                  if (values.length() > 0)
                      values.append(',');
                  values.append(e.toString());
              }
          }
          return values.toString();
      }
docs: Get value as String. Single valued items are converted to a String with
  the toString() Object method. Multi valued entries are converted to a
  comma separated List. No quoting of commas within values is performed.
  
  @param name The entry key.
  @return String value.