ProjectLib/ProjectLibrary/Entites/Book.cs

namespace ProjectLibrary.Entities
{
    using ProjectLibrary.Entities.Enums;

    public class Book
    {
        public int Id { get; private set; }
        public string Author { get; private set; } = string.Empty;
        public string Name { get; private set; } = string.Empty;
        public BookType Type { get; set; } = BookType.None;
        public int LibraryID { get; private set; }

        public static Book CreateEntity(int id, string author, string name, int libraryID, BookType type = BookType.None)
        {
            return new Book
            {
                Id = id,
                Author = author ?? string.Empty,
                Name = name ?? string.Empty,
                LibraryID = libraryID,
                Type = type
            };
        }
    }
}