1, Also, because transactions can be named, undoable actions inherit their names from current transaction.

2, Making this function undoable would also be relatively easy to implement and highly desirable.

3, This change is not undoable. Are you sure you want to proceed?

4, Memory is very full. The previous operation is no longer undoable.

5, The Command pattern implementation supports a request log, a queueing mechanism and undoable operations.

6, As a result, the undo engine has control over the duration of an undoable action.

7, Encapsulate a request as an object, thereby letting you parameterize clients with different requests, queue or log requests, and support undoable operations.

8, Don't accept the limitations of other people who chaim things are undoable or unchangeable.