code: public Broadcast stopBroadcast(String broadcastId) throws OpenTokException {
          if (StringUtils.isEmpty(broadcastId)) {
              throw new InvalidArgumentException("Broadcast id is null or empty");
          }
          String broadcast = this.client.stopBroadcast(broadcastId);
          try {
              return broadcastReader.readValue(broadcast);
          } catch (Exception e) {
              throw new RequestException("Exception mapping json: " + e.getMessage());
          }
      }
docs: Use this method to stop a live broadcast of an OpenTok session.
  Note that broadcasts automatically stop 120 minutes after they are started.
  <p>
  For more information on broadcasting, see the
  <a href="https://tokbox.com/developer/guides/broadcast/">Broadcast developer guide.</a>
  
  @param broadcastId The broadcast ID of the broadcasting session
  
  @return The Broadcast object. This object includes properties defining the archive, including the archive ID.