shutdown
System pressure is beyond critical, so the capture system has shut down.
Declaration
static let shutdown: AVCaptureDevice.SystemPressureState.LevelDiscussion
When system pressure reaches this level, the capture system automatically shuts down, causing a session interruption. Use the AVCaptureSessionInterruptionSystemPressureStateKey in the interruption notification’s userInfo dictionary to find details about the system pressure factors causing the interruption.