public async Task RequestsCorrectUrlWithRepositoryId()
            {
                var gitHubClient = Substitute.For<IGitHubClient>();
                var client = new ObservableBlobClient(gitHubClient);

                client.Get(1, "123456ABCD");

                gitHubClient.Git.Blob.Received().Get(1, "123456ABCD");
            }
            public void GetsFromClientIssueComment()
            {
                var gitHubClient = Substitute.For<IGitHubClient>();
                var client = new ObservableBlobClient(gitHubClient);

                client.Get("fake", "repo", "123456ABCD");

                gitHubClient.GitDatabase.Blob.Received().Get("fake", "repo", "123456ABCD");
            }
            public void RequestsCorrectUrl()
            {
                var gitHubClient = Substitute.For<IGitHubClient>();
                var client = new ObservableBlobClient(gitHubClient);

                client.Get("fake", "repo", "123456ABCD");

                gitHubClient.Git.Blob.Received().Get("fake", "repo", "123456ABCD");
            }
            public async Task EnsuresArguments()
            {
                var client = new ObservableBlobClient(Substitute.For<IGitHubClient>());

                await Assert.ThrowsAsync<ArgumentNullException>(() => client.Get(null, "name", "123456ABCD").ToTask());
                await Assert.ThrowsAsync<ArgumentException>(() => client.Get("", "name", "123456ABCD").ToTask());
                await Assert.ThrowsAsync<ArgumentNullException>(() => client.Get("owner", null, "123456ABCD").ToTask());
                await Assert.ThrowsAsync<ArgumentException>(() => client.Get("owner", "", "123456ABCD").ToTask());
                await Assert.ThrowsAsync<ArgumentNullException>(() => client.Get("owner", "name", null).ToTask());
                await Assert.ThrowsAsync<ArgumentException>(() => client.Get("owner", "name", "").ToTask());
            }