code: public Object attemptTrade(String summonerInternalName, int championId) {
          return client.sendRpcAndWait(SERVICE, "attemptTrade", summonerInternalName, championId, false);
      }
docs: Attempt to trade with the target player
  @param summonerInternalName The summoner's internal name, as sent by {@link #getPotentialTraders()}
  @param championId Unknown - id of sent champion? id of trade?
  @return unknown