public void TestMethodUpdateUser()
 {
     try
     {
         var dataStore = new InMemoryDataStore();
         var user      = new User {
             UserName = "******"
         };
         int id = dataStore.AddOrUpdateUser(user);
         Assert.IsTrue(id > 0);
         var loadUser = dataStore.LoadUser(id);
         loadUser.UserName = "******";
         int newid       = dataStore.AddOrUpdateUser(loadUser);
         var updatedUser = dataStore.LoadUser(newid);
         Assert.IsTrue(updatedUser.UserId == id && string.Equals(updatedUser.UserName, loadUser.UserName), "Load user is not the same");
     }
     catch (Exception exception)
     {
         Debug.WriteLine(format: "Can't update user {0}", args: exception);
         throw;
     }
 }
 public void TestMethodAddUserWithEmptyName()
 {
     try
     {
         var dataStore = new InMemoryDataStore();
         var user      = new User {
             UserName = null
         };
         dataStore.AddOrUpdateUser(user);
     }
     catch (ArgumentNullException exception)
     {
         Assert.IsTrue(string.Equals(exception.Message, "user name can't be null", StringComparison.OrdinalIgnoreCase));
     }
     catch (Exception exception)
     {
         Debug.WriteLine(format: "Can't add user {0}", args: exception);
         throw;
     }
 }