/// <summary>
 /// Initializes a new instance of the <see cref="CategoryManager"/> class.
 /// </summary>
 public CategoryManager()
 {
     this.categoryDalManager = new CategoryDalManager();
 }
 /// <summary>
 /// Initializes a new instance of the <see cref="BookDalManager"/> class.
 /// </summary>
 public BookDalManager()
 {
     sqlDalManager = new SqlDalManager();
     categoryDalManager = new CategoryDalManager();
 }