code: public void disablePresence(String privateKey, String channel,
  			OnDisablePresence callback) throws OrtcNotConnectedException {
  		if (!this.isConnected) {
  			throw new OrtcNotConnectedException();
  		} else {
  			String presenceUrl = this.isCluster ? this.clusterUrl : this.url;
  
  			Ortc.disablePresence(presenceUrl, this.isCluster, this.applicationKey, privateKey, channel, this.proxy, callback);
  		}
  	}
docs: Disables presence for the specified channel.
  
  <pre>
  Ortc.disablePresence(&quot;PRIVATE_KEY&quot;, &quot;CHANNEL&quot;, new onDisablePresence() {
  
  public void run(Exception error, String result) {
  if (error != null) {
  System.out.println(error.getMessage());
  } else {
  System.out.println(result);
  
  }
  }
  });
  </pre>
  
  @param privateKey
  The private key provided when the ORTC service is purchased.
  @param channel
  Channel to disable presence
  @param callback
  Callback with error and result.
  @throws ibt.ortc.extensibility.exception.OrtcNotConnectedException