public void GetUsersApprovalRequests_GetCorrectItems()
        {
            // Arrange
            var context = this.ServiceProvider.GetRequiredService <WmipDbContext>();
            var user1   = new User()
            {
                Id = "1"
            };
            var user2 = new User()
            {
                Id = "2"
            };
            var pendingSong = new Song {
                ApprovalStatus = ApprovalStatus.Pending, ArtistId = user1.Id
            };
            var approvedSong = new Song {
                ApprovalStatus = ApprovalStatus.Approved, ArtistId = user1.Id
            };
            var rejectedSong = new Song {
                ApprovalStatus = ApprovalStatus.Rejected, ArtistId = user2.Id
            };
            var pendingAlbum = new Album {
                ApprovalStatus = ApprovalStatus.Pending, ArtistId = user2.Id
            };
            var approvedAlbum = new Album {
                ApprovalStatus = ApprovalStatus.Approved, ArtistId = user1.Id
            };
            var rejectedAlbum = new Album {
                ApprovalStatus = ApprovalStatus.Rejected, ArtistId = user1.Id
            };

            context.Songs.AddRange(pendingSong, approvedSong, rejectedSong);
            context.Albums.AddRange(pendingAlbum, approvedAlbum, rejectedAlbum);
            context.SaveChanges();
            var approvalService = new ApprovalService(context);

            // Act
            var results = approvalService.GetUsersApprovalRequests(user1.Id);

            // Assert
            Assert.Equal(4, results.Count());
            Assert.True(results.All(r => r.ArtistId == user1.Id));
        }