Upload content type template throgh CSOM

A few years ago I bloged, read it there, on how through server site code could upload new content types templates. This snippet of code do it through CSOM.

 1 string targetUrl = "";
 2 string username = "";
 3 string password = "";
 4 string contentTypeId = "0x01010043A8F0AB23DEB745AF7BF9D49A69F638";
 5 string templatePath = "";
 6 
 7 using (ClientContext clientContext = new ClientContext(targetUrl))
 8 {
 9     SecureString pwd = new SecureString();
10     foreach (char c in password.ToCharArray()) pwd.AppendChar(c);
11 
12     //clientContext.Credentials = new NetworkCredential(username, pwd);
13     clientContext.Credentials = new SharePointOnlineCredentials(username, pwd);
14     clientContext.RequestTimeout = Timeout.Infinite;
15 
16     FileInfo file = new FileInfo(templatePath);
17 
18     ContentType contentType = clientContext.Web.ContentTypes.GetById(contentTypeId);
19     Web web = clientContext.Web;
20 
21     clientContext.Load(contentType, c => c.Name);
22     clientContext.Load(web, w => w.ServerRelativeUrl);
23     clientContext.ExecuteQuery();
24 
25     string resourcePath = string.Format("{0}_cts/{1}", web.ServerRelativeUrl, contentType.Name);
26 
27     using (FileStream stream = file.OpenRead())
28     {
29 
30         FileCreationInformation templateFile = new FileCreationInformation()
31         {
32             ContentStream = stream,
33             Url = file.Name,
34             Overwrite = true
35         };
36 
37         Folder folder = web.GetFolderByServerRelativeUrl(resourcePath);
38         folder.Files.Add(templateFile);
39         contentType.DocumentTemplate = file.Name;
40         contentType.Update(false);
41         clientContext.ExecuteQuery();
42     }
43 }