extension LiveCameraViewController: LiveCameraDelegate {

    private var ageRequest: VNCoreMLRequest = {
        let model = try! VNCoreMLModel(for: AgeNet().model)
        return VNCoreMLRequest(model: model) { request, error in
            if let observation = request.results?.first as? VNClassificationObservation {
                // do something
            }
        }
    }()

    private var genderRequest: VNCoreMLRequest = {
        let model = try! VNCoreMLModel(for: GenderNet().model)
        return VNCoreMLRequest(model: model) { request, error in
            if let observation = request.results?.first as? VNClassificationObservation {
                // do something
            }
        }
    }()

    func didUpdateBuffer(_ buffer: CMSampleBuffer, on camera: LiveCamera) {
        let image = UIImage(buffer: CMSampleBufferGetImageBuffer(buffer)!)?
            .rescaled(width: inputImageScale, height: inputImageScale)
            .cgImage
        let handler = VNImageRequestHandler(cgImage: image!)
        try? handler.perform([ageRequest, genderRequest])
    }
}