public bool DeleteManufacturer(Manufacturer manufacturer)
 {
     _manufacturerContext.Remove(manufacturer);
     return(Save());
 }
 public bool DeleteItem(Item item)
 {
     _itemContext.Remove(item);
     return(Save());
 }
 public bool DeleteCategory(Category category)
 {
     _categoryContext.Remove(category);
     return(Save());
 }