Give back the customer change$$

When the customer is done purchasing items, the machine should give back the remaining balance to the customer. Implement a method called output$\_$change that checks if there is any change to be given back and, if so$,$ prints the change in the following format:

Change: $\{$CHANGE$\}$

It should then set the customer$$s balance to $0\mathrm{.}0,$ indicating the change has been given back to the customer.

If no change needs to be given back, it should simply print the message:

No change

Testing recommendations for output$\_$change:

When there is change $($i$.$e$.,$ balance $>0)$

When there is no change $($i$.$e$.,$ balance $=0)$

$1$i$.$ Remove an item from the vending machine$$

If a snack is not selling well, the owner may want to remove it completely from the selection so it will no longer be restocked. Implement a method called remove$\_$item that takes the name of a snack as a parameter, and removes it from the vending machine. If successful, it should print the following message:

$\{$ITEM$\}$ removed from inventory

If the item to be removed does not exist in the machine, it should print the following message:

Invalid item

Testing recommendations for remove$\_$item:

Removing a valid item

Removing an invalid item