public async Task GetFriendships()
        {
            try
            {
                _context.Database.EnsureCreated();

                var repository = new DatasetRepository(_context);
                await repository.AddDatasetAsync("dataset 1", new List <string>() { "1 0", "1 2" });

                var datasets = await repository.GetDatasetsAsync();

                var friendships = await repository.GetFriendshipsAsync(datasets.Single().Id);

                Assert.Equal(2, friendships.Count());
            }
            finally
            {
                _context.Database.EnsureDeleted();
            }
        }
        public async Task GetUsersAsync()
        {
            try
            {
                _context.Database.EnsureCreated();

                var repository = new DatasetRepository(_context);
                await repository.AddDatasetAsync("dataset 1", new List <string>() { "1 0", "1 2" });

                var datasets = await repository.GetDatasetsAsync();

                var users = await repository.GetUsersAsync(datasets.Single().Id);

                Assert.Equal(3, users.Count);
                Assert.Equal(new string[] { "0", "1", "2" }, users.Select(c => c.Id).ToArray());
            }
            finally
            {
                _context.Database.EnsureDeleted();
            }
        }