internal void UpdatePainting(Painting painting)
 {
     _context.Update(painting);
     _context.SaveChanges();
 }
 internal void Delete(Painting painting)
 {
     _context.Painting.Remove(painting);
     _context.SaveChanges();
 }
 internal void Add(Painting painting)
 {
     _context.Add(painting);
     _context.SaveChanges();
 }