code: public static String join(List<? extends EncodedPair> pairs, char pairSep){
          return join(pairs, pairSep, '=', false, false);
      }
docs: Joins the given list of encoded pairs using "=" for name/value separator and pairSep for pair separator.
  @param pairs list of encoded pair to join
  @param pairSep character to use to join pairs
  @return joined pairs