Possible values are:
Specifies that the method starts a new conversation. A call to this method creates a new conversation ID and context, and resets its idle and age timer.
Specifies that the method is part of a conversation in progress. A call to this method resets the idle timer. This method must always be called after the start method and before the finish method.
Specifies that the method explicitly finishes a conversation in progress.
Default value is Phase.CONTINUE