establishes a communication channel with an iot hub . if a channel is already open , the function shall do nothing . concode_field_sep MqttIotHubConnection mqttIotHubConnection concode_elem_sep Queue<IotHubOutboundPacket> waitingList concode_elem_sep MqttTransportState state concode_elem_sep DeviceClientConfig config concode_elem_sep Queue<IotHubCallbackPacket> callbackList concode_field_sep void sendMessages concode_elem_sep void invokeCallbacks concode_elem_sep void handleMessage concode_elem_sep boolean isEmpty concode_elem_sep void close concode_elem_sep void addMessage
void function ( ) { if ( this . state == MqttTransportState . OPEN ) { return ; } this . mqttIotHubConnection = new MqttIotHubConnection ( this . config ) ; this . mqttIotHubConnection . open ( ) ; this . state = MqttTransportState . OPEN ; }