Chapter 4, Problem 14E

Add a method called checklndex to the MusicOrganizer class. It takes a single integer parameter and checks whether it is a valid index for the current state of the collection. To be valid, the parameter must lie in the range 0 to size $()-1.$

If the parameter is not valid, then it should print an error message saying what the valid range is. If the index is valid, then it prints nothing. Test your method on the object bench with both valid and invalid parameters. Does your method still work when you check an index if the collection is empty?