func downloadImage(urlString: String, completion: @escaping (Result<UIImage, RequestError>)->Void) {
var request = URLRequest(url: URL(string: urlString)!)
request.httpMethod = "GET"
let task = URLSession.shared.dataTask(with: request, completionHandler: {
data, response, error in
guard error == nil else {
completion(.failure(.networkError))
return
}
guard data != nil else {
completion(.failure(.networkError))
return
}
guard let image = UIImage(data: data!) else {
completion(.failure(.networkError))
return
}
completion(.success(image))
})
task.resume()
}