For the class Employee example provided in tutorial $3\mathrm{.}1\mathrm{.}5,$ if for auditing purposes we needed to keep track of how many last name changes have been made for an employee, what code segments could implement this task?

def $\_\_$init$\_\_($ fname, lname$,$ empid, title, sal$)$:

lastname$\_$changes $=0$

def set$\_$lastname$($lname$)$:

if len$($lname$)>0$:

lastname $=$ lname

lastname$\_$changes $+=1$

def get$\_$lastname$\_$changes$()$:

return lastname$\_$changes

def $\_\_$init$\_\_($fname$,$ lname$,$ empid, title, sal$)$:

self.lastname$\_$changes $=0$

def set$\_$lastname$($lname$)$:

if len$($lname$)>0$:

self.lastname $=$ lname

self.lastname$\_$changes $+=1$

def get$\_$lastname$\_$changes$()$:

return self.lastname$\_$changes

def $\_\_$init$\_\_($self$,$ fname, lname$,$ empid, title, sal$)$:

self.lastname$\_$changes $=0$

def set$\_$lastname$($self$,$lname$)$:

if len$($lname$)>0$:

self.lastname $=$ lname

self.lastname$\_$changes $+=1$

def get$\_$lastname$\_$changes$($self$)$:

return self.lastname$\_$changes

def $\_\_$init$\_\_($self$,$ fname, lname$,$ empid, title, sal$)$:

lastname$\_$changes $=0$

def set$\_$lastname$($self$,$lname$)$:

if len$($lname$)>0$:

lastname $=$ lname

lastname$\_$changes $+=1$

def get$\_$lastname$\_$changes$($self$)$:

return lastname$\_$changes