2
Helena 10000 7
LazyGuy 15000 7

undo
list

redo
list

exchangeSalaries Helena LazyGuy
addSalary Helena 5000
fire LazyGuy
list

undo
undo
undo
undo
list

redo
redo
redo
redo
list

undo
undo
changeAnnualLeaves Helena 365
list

redo
list
