private static void Init()
    {
        FilterHierarchyEditor filter = EditorWindow.GetWindow(typeof(FilterHierarchyEditor)) as FilterHierarchyEditor;

        filter.Show();
    }
    static void Init()
    {
        FilterHierarchyEditor filter = (FilterHierarchyEditor)EditorWindow.GetWindow(typeof(FilterHierarchyEditor));

        filter.Show();
    }