System.Net.WebClient.OpenWriteTaskAsync C# (CSharp) Method

        public System.Threading.Tasks.Task<System.IO.Stream> OpenWriteTaskAsync(System.Uri address) { throw null; }
        public System.Threading.Tasks.Task<System.IO.Stream> OpenWriteTaskAsync(string address, string method) { throw null; }

 static async Task WriteStreamAsync(string url)
 {
     using (var client = new WebClient())
     using (var writer = new StreamWriter(await client.OpenWriteTaskAsync(url)))
     {
         await writer.WriteAsync("test=value");
     }
 }