private void CheckGUIDWrite()
 {
     using (var db = new AppDb())
     {
         var itm = new TableGuidType
         {
             uid = new Guid()
         };
         db.TableGuidType.Add(itm);
         db.SaveChanges();
     }
 }
        private void CheckGUIDReadWrite()
        {
            using (var db = new AppDb())
            {
                var itm = new TableGuidType
                {
                    uid = new Guid("3d2a2463-3120-4663-80c8-df3d3e166258")
                };
                db.TableGuidType.Add(itm);
                db.SaveChanges();

                var uid = db.TableGuidType.OrderByDescending(x => x.Id).FirstOrDefault();
                Assert.Equal(uid.uid.ToString(), "3d2a2463-3120-4663-80c8-df3d3e166258");
            }
        }