$$ Program checklist for Sign$$off #$21.$ If the doors are closed, a button press to move from the current floor to the other floor causes the elevator to begin to move $2.$ The elevator doors open automatically when the elevator reaches the first or second floor $3.$ A button request to open the doors while the elevator is moving is ignored $4.$ A button request to move to a different floor while the doors are fully open, opening, or closing, is ignored $5.$ After the doors have been open for $3$ seconds without the Open button being pressed, the doors automatically close. Pressing the Open button while the doors are open resets the count$$down to a fresh $3$ seconds before the doors automatically close. $6.$ The Close button causes the doors to close, regardless of how long they have been open $7.$ More generally, recall that Task $2$ stated: $$Modify your program so that there is no user action that can cause the elevator system to crash with an error.$$ Try hard to cause your program to break, and fix any problems you find, before calling your TA for sign$$off$.8.$ Your program has clean indentation, no ragged edges $9.$ Your code uses meaningful variable names $10.$ Your code is commented to express to the reader the purpose of each section of code.