public virtual void AddNewBook(Book book)
{
if (book == null)
{
throw new ArgumentNullException($"{nameof(book)} is null");
}
var newBook = new AuthorToBook(book, this);
PersonalBooks.Add(newBook);
}
public Book(string bookName, DateTime publicationDate, BookCategory category, IList <Author> authors, string description = null)
{
ValidateInput(bookName, publicationDate, category, description, authors);
foreach (var author in authors)
{
var authorToBook = new AuthorToBook(this, author);
Authors.Add(authorToBook);
}
Category = category;
Name = bookName;
PublicationDate = publicationDate;
}