I have to do a patch request using the HTTP Client in C#.Seems very simple to do a Get request:
var httpclient = GetHttpClient(accessToken.Result);
var response = await
httpclient.GetAsync("https://graph.microsoft.com/v1.0/me/messages");
response.EnsureSuccessStatusCode();
var content = await response.Content.ReadAsStringAsync();
JObject o = JObject.Parse(content);
However for a patch, I cannot find a PatchAsync method, only seems to have POST and PUT.