PnP Core Component - Get Group ID in SharePoint 2016

Please refer to the Introduction to PnP Core Component and OfficeDevPnP.Core for more details. I have created a console application and added SharePointPnPCore2016 NuGet package for the SharePoint 2016 version.
 
Code Snippet
  1. using System;  
  2. using System.Collections.Generic;  
  3. using System.Linq;  
  4. using System.Text;  
  5. using System.Threading.Tasks;  
  6. using Microsoft.SharePoint.Client;  
  7. using OfficeDevPnP.Core;    
  8.   
  9. namespace SP2016PnPCoreComponentDemo  
  10. {  
  11.     class Program  
  12.     {  
  13.         static void Main(string[] args)  
  14.         {  
  15.             // Input Parameters    
  16.             string siteUrl = "http://c7395723754/";  
  17.             string userName = "administrator";  
  18.             string password = "Mf165Nz2WV";  
  19.             string domain = "AD2012";  
  20.             string groupName = "Group created using PnP";  
  21.             
  22.             OfficeDevPnP.Core.AuthenticationManager authMgr = new OfficeDevPnP.Core.AuthenticationManager();  
  23.   
  24.             try  
  25.             {  
  26.                 // Get the client context    
  27.                 using (var ctx = authMgr.GetNetworkCredentialAuthenticatedContext(siteUrl, userName, password, domain))  
  28.                 {  
  29.                     // Get group ID  
  30.                     int groupID= ctx.Web.GetGroupID(groupName);  
  31.                     Console.WriteLine(groupID);  
  32.                     Console.ReadLine();  
  33.                 }  
  34.             }  
  35.   
  36.             catch (Exception ex)  
  37.             {  
  38.                 Console.WriteLine("Error Message: " + ex.Message);  
  39.             }  
  40.         }  
  41.     }  
  42. }