static void Execute()
 {
     if (window == null)
     {
         window = (MassMaterialEditor)GetWindow(typeof(MassMaterialEditor));
     }
     window.Show();
 }
 static void Execute()
 {
     if (window == null)
         window = (MassMaterialEditor)GetWindow(typeof (MassMaterialEditor));
     window.Show();
 }