public int getBookRequestSize(Book book) {
int numberOfBookRequest = 0;
if (borrowedBooks.containsKey(book.getIsbnNumber()))
numberOfBookRequest = borrowedBooks.get(book.getIsbnNumber()).getSizeOfQueue();
return numberOfBookRequest;
}
private boolean isBookBorrowed(Book book) {
return borrowedBooks.containsKey(book.getIsbnNumber());
}