public async Task DeleteFriendInvite()
        {
            using var contextFactory        = new TestTriviaGameContextFactory();
            using TriviaRankContext context = contextFactory.CreateContext();

            var insertedPlayer1 = new Player
            {
                Username  = "******",
                Password  = "******",
                Birthday  = DateTime.Now,
                Points    = 100,
                FirstName = "Bart",
                LastName  = "Simpson"
            };
            var insertedPlayer2 = new Player
            {
                Username  = "******",
                Password  = "******",
                Birthday  = DateTime.Now,
                Points    = 200,
                FirstName = "Milhouse",
                LastName  = "Vanhouten"
            };
            await context.Players.AddAsync(insertedPlayer1);

            await context.Players.AddAsync(insertedPlayer2);

            context.SaveChanges();
            var repo = new OutboxRepository(context);
            await repo.createFriendInvite(insertedPlayer1.Username, insertedPlayer2.Username);

            await repo.deleteFriendInvite(insertedPlayer1.Username, insertedPlayer2.Username);

            Assert.Empty((await repo.getFriendInvites(insertedPlayer2.Id)).Where(p => p.Id == insertedPlayer1.Id));
        }