UnityEditor.SpriteEditorWindow.OnDisable C# (CSharp) Method

        private void OnDisable()
        {
            Undo.undoRedoPerformed = (Undo.UndoRedoCallback) Delegate.Remove(Undo.undoRedoPerformed, new Undo.UndoRedoCallback(this.UndoRedoPerformed));
            if (this.m_RectsCache != null)
            {
                Undo.ClearUndo(this.m_RectsCache);
            }
            this.HandleApplyRevertDialog();
            this.InvalidatePropertiesCache();
            EditorApplication.modifierKeysChanged = (EditorApplication.CallbackFunction) Delegate.Remove(EditorApplication.modifierKeysChanged, new EditorApplication.CallbackFunction(this.ModifierKeysChanged));
            s_Instance = null;
        }