public async Task EnsuresArgumentsNotNull()
            {
                var client = new ObservablePullRequestReviewCommentsClient(Substitute.For<IGitHubClient>());

                var request = new PullRequestReviewCommentRequest();

                await AssertEx.Throws<ArgumentNullException>(async () => await client.GetForRepository(null, "name", request));
                await AssertEx.Throws<ArgumentException>(async () => await client.GetForRepository("", "name", request));
                await AssertEx.Throws<ArgumentNullException>(async () => await client.GetForRepository("owner", null, request));
                await AssertEx.Throws<ArgumentException>(async () => await client.GetForRepository("owner", "", request));
                await AssertEx.Throws<ArgumentNullException>(async () => await client.GetForRepository("owner", "name", null));
            }
            public async Task RequestsCorrectUrl()
            {
                var firstPageUrl = new Uri("repos/fakeOwner/fakeRepoName/pulls/comments", UriKind.Relative);
                var secondPageUrl = new Uri("https://example.com/page/2");
                var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
                var firstPageResponse = new ApiResponse<List<PullRequestReviewComment>>
                (
                    CreateResponseWithApiInfo(firstPageLinks),
                    new List<PullRequestReviewComment>
                    {
                        new PullRequestReviewComment(1),
                        new PullRequestReviewComment(2),
                        new PullRequestReviewComment(3)
                    }
                );
                var thirdPageUrl = new Uri("https://example.com/page/3");
                var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
                var secondPageResponse = new ApiResponse<List<PullRequestReviewComment>>
                (
                    CreateResponseWithApiInfo(secondPageLinks),
                    new List<PullRequestReviewComment>
                    {
                        new PullRequestReviewComment(4),
                        new PullRequestReviewComment(5),
                        new PullRequestReviewComment(6)
                    });
                var lastPageResponse = new ApiResponse<List<PullRequestReviewComment>>
                (
                    new Response(),
                    new List<PullRequestReviewComment>
                    {
                        new PullRequestReviewComment(7),
                        new PullRequestReviewComment(8)
                    }
                );

                var gitHubClient = Substitute.For<IGitHubClient>();

                gitHubClient.Connection.Get<List<PullRequestReviewComment>>(firstPageUrl,
                    Arg.Is<Dictionary<string, string>>(d => d.Count == 3
                        && d["direction"] == "desc"
                        && d["since"] == "2013-11-15T11:43:01Z"
                        && d["sort"] == "updated"), null)
                    .Returns(Task.Factory.StartNew<IApiResponse<List<PullRequestReviewComment>>>(() => firstPageResponse));
                gitHubClient.Connection.Get<List<PullRequestReviewComment>>(secondPageUrl, null, null)
                    .Returns(Task.Factory.StartNew<IApiResponse<List<PullRequestReviewComment>>>(() => secondPageResponse));
                gitHubClient.Connection.Get<List<PullRequestReviewComment>>(thirdPageUrl, null, null)
                    .Returns(Task.Factory.StartNew<IApiResponse<List<PullRequestReviewComment>>>(() => lastPageResponse));

                var client = new ObservablePullRequestReviewCommentsClient(gitHubClient);

                var request = new PullRequestReviewCommentRequest
                {
                    Direction = SortDirection.Descending,
                    Since = new DateTimeOffset(2013, 11, 15, 11, 43, 01, 00, new TimeSpan()),
                    Sort = PullRequestReviewCommentSort.Updated,
                };

                var results = await client.GetForRepository("fakeOwner", "fakeRepoName", request).ToArray();

                Assert.Equal(8, results.Length);
                gitHubClient.Connection.Received(1).Get<List<PullRequestReviewComment>>(firstPageUrl,
                    Arg.Is<Dictionary<string, string>>(d => d.Count == 3
                        && d["direction"] == "desc"
                        && d["since"] == "2013-11-15T11:43:01Z"
                        && d["sort"] == "updated"), null);
                gitHubClient.Connection.Received(1).Get<List<PullRequestReviewComment>>(secondPageUrl, null, null);
                gitHubClient.Connection.Received(1).Get<List<PullRequestReviewComment>>(thirdPageUrl, null, null);
            }
            public async Task RequestsCorrectUrlWithoutSelectedSortingArguments()
            {
                var firstPageUrl = new Uri("repos/fakeOwner/fakeRepoName/pulls/comments", UriKind.Relative);
                var secondPageUrl = new Uri("https://example.com/page/2");
                var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
                var firstPageResponse = new ApiResponse<List<PullRequestReviewComment>>
                (
                    CreateResponseWithApiInfo(firstPageLinks),
                    new List<PullRequestReviewComment>
                    {
                        new PullRequestReviewComment(1),
                        new PullRequestReviewComment(2),
                        new PullRequestReviewComment(3)
                    }
                );
                var thirdPageUrl = new Uri("https://example.com/page/3");
                var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
                var secondPageResponse = new ApiResponse<List<PullRequestReviewComment>>
                (
                    CreateResponseWithApiInfo(secondPageLinks),
                    new List<PullRequestReviewComment>
                    {
                        new PullRequestReviewComment(4),
                        new PullRequestReviewComment(5),
                        new PullRequestReviewComment(6)
                    });
                var lastPageResponse = new ApiResponse<List<PullRequestReviewComment>>
                (
                    new Response(),               
                    new List<PullRequestReviewComment>
                    {
                        new PullRequestReviewComment(7),
                        new PullRequestReviewComment(8)
                    }
                );

                var gitHubClient = Substitute.For<IGitHubClient>();

                gitHubClient.Connection.Get<List<PullRequestReviewComment>>(firstPageUrl,
                    Arg.Is<Dictionary<string, string>>(d => d.Count == 2
                        && d["direction"] == "asc"
                        && d["sort"] == "created"), null)
                    .Returns(Task.Factory.StartNew<IApiResponse<List<PullRequestReviewComment>>>(() => firstPageResponse));
                gitHubClient.Connection.Get<List<PullRequestReviewComment>>(secondPageUrl, null, null)
                    .Returns(Task.Factory.StartNew<IApiResponse<List<PullRequestReviewComment>>>(() => secondPageResponse));
                gitHubClient.Connection.Get<List<PullRequestReviewComment>>(thirdPageUrl, null, null)
                    .Returns(Task.Factory.StartNew<IApiResponse<List<PullRequestReviewComment>>>(() => lastPageResponse));

                var client = new ObservablePullRequestReviewCommentsClient(gitHubClient);

                var results = await client.GetForRepository("fakeOwner", "fakeRepoName").ToArray();

                Assert.Equal(8, results.Length);
                gitHubClient.Connection.Received(1).Get<List<PullRequestReviewComment>>(firstPageUrl,
                    Arg.Is<Dictionary<string, string>>(d => d.Count == 2
                        && d["direction"] == "asc"
                        && d["sort"] == "created"), null);
                gitHubClient.Connection.Received(1).Get<List<PullRequestReviewComment>>(secondPageUrl, null, null);
                gitHubClient.Connection.Received(1).Get<List<PullRequestReviewComment>>(thirdPageUrl, null, null);
            }