iOS 14.4.2, Apple iPhone8, SBPowerDownViewController

Dear forum members,

I have an apple full filesystem backup of an iPhone8. In the course of my research I came across the entry

"SBPowerDownViewController"

and tried to find out what it does on the device. Unfortunately I could not find any helpful entries on the internet.

Do any of you know what the function of this controller is?

Thanks and greetings
PlanB