EyeonTips:Script/Reference/Applications/Fusion/Classes/Composition/StartUndo

From VFXPedia

Note: Actual changes must be made to the composition (forcing a "dirty" event) before the undo will be added to the stack. For example, this:

   composition:StartUndo("Testing.")  print("This is a test.")  composition:EndUndo()

won't add an undo to the list, but this:

   composition:StartUndo("Testing.")  ld = Loader()  composition:EndUndo()

will -- and you'll see it show up in the Edit menu as an undo action. This caused me some confusion, so adding it here.