import UIKit
import AVFoundation

class PreviewView: UIView {
    var videoPreviewLayer: AVCaptureVideoPreviewLayer {
        guard let layer = layer as? AVCaptureVideoPreviewLayer else {
            fatalError("Expected AVCaptureVideoPreviewLayer.")
        }
        return layer
    }

    var session: AVCaptureSession? {
        get { videoPreviewLayer.session }
        set { videoPreviewLayer.session = newValue }
    }

    override class var layerClass: AnyClass {
        AVCaptureVideoPreviewLayer.self
    }
}