private void OnGUI()
        {
            if (GUILayout.Button("Create New Category"))
            {
                CreateCategoryWindow.OpenMenu();
            }

            if (GUILayout.Button("Rename Existing Category"))
            {
                RenameCategoryWindow.OpenMenu();
            }
        }
 public static void OpenMenu()
 {
     window = GetWindow <RenameCategoryWindow>();
     window.selectedCategoryValue = 0;
 }