OAuth2 C# RestSharp

oauth2-restsharp.cs

string url = "https://myurl.com";
string client_id = "client_id";
string client_secret = "client_secret";
//request token
var restclient = new RestClient(url);
RestRequest request = new RestRequest("request/oauth") {Method = Method.POST};
request.AddHeader("Accept", "application/json");
request.AddHeader("Content-Type", "application/x-www-form-urlencoded");
request.AddParameter("client_id", client_id);
request.AddParameter("client_secret", client_secret);
request.AddParameter("grant_type", "client_credentials");
var tResponse = restclient.Execute(request);
var responseJson = tResponse.Content;
var token = JsonConvert.DeserializeObject<Dictionary<string,object>>(responseJson)["access_token"].ToString();
return token.Length > 0 ? token : null;