Optional issuerThe issuer of this event, as passed into the according API method. 'api' by default if no issuer was specified.
The volume before the event has been triggered.
The new selected volume.
The timestamp (in milliseconds) when this event was fired.
Event type.
Events which can be triggered by user interaction as well as internally.
The issuer is to determine whether this was triggered internally ('api') or by the UI ('ui')