@Override
 void execute(Library library, Console console) {
   if (library.numberOfBooksCheckedOut() == 0) {
     console.printMessage("There are no books available for return");
     return;
   }
   console.printMessage("Books available for return:");
   console.printLibraryItemList(library.checkedOutBooks());
   console.printMessage("> Enter book number: ");
   Integer selection = getAsInteger(console.getUserCommand());
   if (selection != null && library.bookIsCheckedOut(selection)) {
     library.returnBook(selection);
     console.printMessage("Thank you for returning the book");
   } else {
     console.printMessage("That is not a valid book to return");
   }
 }
 private void setUserInput(String inputs[]) {
   List<String> inputList = Arrays.asList(inputs);
   when(console.getUserCommand()).thenAnswer(AdditionalAnswers.returnsElementsOf(inputList));
 }