Revert font to its previous saved state

Is there a way to revert a font that has been temporarily modified to its previous saved state? Or, is there another recommended approach to make temporary modifications to a font and leave it untouched after all those? Thanks!

You could call document.revertDocumentToSaved_().

Glyphs.documents[0].revertDocumentToSaved_() asks for an argument:
Traceback (most recent call last):
File “”, line 1, in
TypeError: Need 1 arguments, got 0

If I pass 0 or 1 as argument it seems not to make any difference, the dialog shows up waiting for the user input.
Would be possible to revert directly without the dialog?

Just add None