Aptitude Undo Operation

While in the Aptitude interactive mode, what can you do to undo an accidentally operation. For e.g. a press of the minus key on a large package group! Aptitude does now allow you do perform a mass undo of the action you just initiated. To undo do the following:

# First Quit aptitude interface
#
# Backup current pkgstates file
cp /var/lib/aptitude/pkgstates /tmp/
#
# Replace with copy
cp /var/backups/aptitude.pkgstates.0 /var/lib/aptitude/pkgstates