The action to execute. It is up to the trigger's implementation to decide when to call this action. The action should never be called by anything but the trigger. Actions can be implemented without using this property, but in addition notifyListenersOfEvent needs to be used to notify any listeners of the Trigger that an action was executed.
In future subclasses of this property to be provided, this action block will be used to give developers control of an action when a set of criteria has been met. For example, a subclass of this may be a battery threshold trigger. Once the battery passes some threshold developers will be able to define the action they want to trigger.
Begins trigger activity including monitoring the criteria required to trigger the action. When subclassing, the super class's start method should be called on the first line.
Ends all trigger activities including monitoring the criteria required to trigger the action. When subclassing, the super class's stop method should be called at the end.