public void Test_LockForEditing()
 {
     try
     {
         User iUser = UsersRepository.Instance.GetAllUsers().First();
         Assert.IsNull(iUser.Lock_);
         using (DataContext testContext = new DataContext(connection))
         {
             User testUser = testContext.Users.Find(iUser.ID);
             testContext.Lock<User>(testUser);
             testContext.Entry(testUser).Reload();
             Assert.IsNotNull(testUser.Lock_);
             testContext.Unlock<User>(testUser);
             Assert.IsNull(iUser.Lock_);
         }
     }
     catch (Exception ex)
     {
         Assert.Fail(ex.Message);
     }
 }