DBImageDecoderUsingWithUrlSession.swift

let imageDecoder = DBImageDecoder()

var imageData = Data()

func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
    imageData.append(data)
    imageDecoder.setData(imageData, allDataReceived: false)
}

func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
    imageDecoder.setData(imageData, allDataReceived: true)
}