Saving the State of a custom Window

Hi,

I'm trying to learn the basics of custom windows and node editors.
With the code below I get two windows that I can drag, however when I close and
reopen the main window or reopen Unity, they are reset and start in the positions
specified in the script (which of course makes sense).

How would I approach saving the state of the window, such that it survives reopening
Unity?
(I do understand that I could save the current rects of the windows and then retrieve
them on reloading, but with more complex windows this will be very tedious and I'm
wondering if there is some buildIn method for custom editors which solves this)

Code (CSharp):

1. public class TestEditorWIndow : EditorWindow
2. {
3.     Rect window1 = new Rect(10, 10, 100, 100);
4.     Rect window2 = new Rect(210, 210, 100, 100);
5.  
6.     [MenuItem("Window/EditorTestWindow")]
7.     private static void OpenWindow()
8.     {
9.         TestEditorWIndow window = GetWindow<TestEditorWIndow>();
10.     }
11.  
12.     private void OnGUI()
13.     {
14.         BeginWindows();
15.  
16.         window1 = GUI.Window(1, window1, DrawNodeWindow, "Window 1");
17.         window2 = GUI.Window(2, window2, DrawNodeWindow, "Window 2");
18.  
19.         EndWindows();
20.  
21.         TestEditorWIndow window = GetWindow<TestEditorWIndow>();
22.     }
23.  
24.     void DrawNodeWindow(int id)
25.     {
26.         GUI.DragWindow();
27.         GUI.Label(new Rect(10, 20, 100, 20), "My Window");
28.     }
29. }

 

I think this guy covers it towards the end of his setup:

 

Thank You. That's an interesting tutorial.