internal void OnEnable()
        {
            PResourceManager.SetDefaultResourcePath("Assets/Res/Scripts/Editor/res/");
            Texture icon = PResourceManager.LoadTexture(EditorGUIUtility.isProSkin
                ? "Textures/Icon_Dark.png"
                : "Textures/Icon_Light.png");

            titleContent = new GUIContent("Machine", icon);
            minSize      = new Vector2(150, 100);
            MachineHierachyCenter.Start();
            PPaintCenter.ClientRepaints -= Repaint;
            PPaintCenter.ClientRepaints += Repaint;
        }
 internal void OnDestroy()
 {
     PPaintCenter.ClientRepaints -= Repaint;
     MachineHierachyCenter.Stop();
 }
 internal void OnGUI()
 {
     MachineHierachyCenter.OnGUI(position, this == focusedWindow);
 }