Keep Windows Forms Singleton via Mutex key word

using System;using System.Collections.Generic;using System.Linq;using System.Threading;using System.Threading.Tasks;using System.Windows.Forms;namespace WindowsFormsApplication3{    static class Program    {        /// <summary>        /// The main entry point for the application.        /// </summary>        [STAThread]        static void Main()        {            Application.EnableVisualStyles();            Application.SetCompatibleTextRenderingDefault(false);            const string appName = "WindowsFormsApplication3";            bool createdNew;            Mutex mut = new Mutex(true, appName, out createdNew);            if (!createdNew)            {                MessageBox.Show($"WindowsFormsApplication3 is already running!", "Multiple Instances");                return;            }            Application.Run(new Form1());        }    }}b