What is setLocationManager() in <UserLocation /> and how to use it.

[Stophface]

I am not quite sure what setLocationManager() is used for?
Assuming the user has granted location permission Always and the App goes into the background. When I use <UserLocation /> and the map screen is not unmounted (which is pretty common for a i.e. <TabNavigator />, it will constantly monitor the users location, eventhough the user has put the App into the background. This is not what I want. I only want to monitor the users location once the App is active/actually opened. Can I use setLocationManager() to turn this behaviour off?

Additionally, I am not sure how to use setLocationManager(). It is a method <Mapbox.UserLocation />, but how to trigger it?