Async JSON iteration in C#

gistfile1.txt

using (WebClient client = new WebClient())
            {
                client.Headers = new WebHeaderCollection{{"x-access-token", "..."}};
                await using (Stream stream = client.OpenRead("http://...dump.json"))
                using (StreamReader streamReader = new StreamReader(stream ?? throw new NullJsonDumpException()))
                using (JsonTextReader reader = new JsonTextReader(streamReader))
                {
                    reader.SupportMultipleContent = true;

                    var serializer = new JsonSerializer();
                    while (reader.Read())
                    {
                        if (reader.TokenType == JsonToken.StartObject)
                        {
                            yield return serializer.Deserialize<JObject>(reader);
                        }
                    }
                }
            }