The open(short) method must be the first method called after creating a QAManager.
If a database connection error is detected, you can re-open a QAManager by calling the close method followed by the open method.
When re-opening a QAManager, you do not need to re-create it, reset the properties, or reset the message listeners. The properties
of the QAManager cannot be changed after the first open, and subsequent open calls must supply the same acknowledgement mode.