import AVFoundation import Foundation @available(tvOS 17.0, *) protocol DeviceUnit { associatedtype Output: AVCaptureOutput var track: UInt8 { get } var input: AVCaptureInput? { get } var output: Output? { get } var device: AVCaptureDevice? { get } var connection: AVCaptureConnection? { get } init(_ track: UInt8, device: AVCaptureDevice) throws }