Clear the stack.
Optional
notify: booleanReturns true
if there are undo actions on the stack.
Sets repeatable action.
A repeatable action is an action that a user can do multiple times 'usually on various selections'. For example styling a field adding a similar operation to the undo stack is usually expected and has to be done done separately by the caller.
Undo the last actions on the stack.
Optional
count: numbernumber of actions to undo, default is 1.
A stack of undo/redo actions.