Can I add a role for RLS Using XMLA Endpiont and C#?

I have managed to create a new semantic model using XMLA Endpoint and C# but now I need to be able to create Roles for RLS using the same method.  Is this allowed?  And if so How can I go about doing it? 

Below is my simple code in creating the semantic model.

If I can call a REST API tha twould work too... I just didn't see any that would work.

   string newDatabaseName = server.Databases.GetNewName(DatabaseName);

   var database = new Microsoft.AnalysisServices.Database()
   {
       Name = newDatabaseName,
       ID = newDatabaseName,
       CompatibilityLevel = 1520,
       StorageEngineUsed = Microsoft.AnalysisServices.StorageEngineUsed.TabularMetadata,
       Model = new Model()
       {
           Name = DatabaseName + "-Model",
           Description = "A Demo Tabular data model with 1520 compatibility level."
       }
   };

   server.Databases.Add(database);
   database.Update(Microsoft.AnalysisServices.UpdateOptions.ExpandFull);