question: open amqp sender concode_field_sep String sasToken concode_elem_sep String hostName concode_elem_sep ExecutorService executor concode_elem_sep AmqpSend amqpMessageSender concode_elem_sep IotHubConnectionString iotHubConnectionString concode_elem_sep String userName concode_field_sep CompletableFuture<Void> sendAsync concode_elem_sep CompletableFuture<Void> openAsync concode_elem_sep ServiceClient createFromConnectionString concode_elem_sep CompletableFuture<Void> closeAsync concode_elem_sep void close concode_elem_sep void send concode_elem_sep FeedbackReceiver getFeedbackReceiver
target: void function ( ) { if ( this . amqpMessageSender == null ) { throw new IOException ( "srini_string" ) ; } this . amqpMessageSender . open ( ) ; }