Create() public method

Creates a comment on a pull request review.
http://developer.github.com/v3/pulls/comments/#create-a-comment
public Create ( long repositoryId, int number, PullRequestReviewCommentCreate comment ) : IObservable
repositoryId long The Id of the repository
number int The Pull Request number
comment PullRequestReviewCommentCreate The comment
return IObservable
            public async Task EnsuresNonNullArguments()
            {
                var gitHubClient = Substitute.For<IGitHubClient>();
                var client = new ObservablePullRequestReviewCommentsClient(gitHubClient);

                string body = "Comment content";
                string commitId = "qe3dsdsf6";
                string path = "file.css";
                int position = 7;

                var comment = new PullRequestReviewCommentCreate(body, commitId, path, position);

                Assert.Throws<ArgumentNullException>(() => client.Create(null, "name", 1, comment));
                Assert.Throws<ArgumentNullException>(() => client.Create("owner", null, 1, comment));
                Assert.Throws<ArgumentNullException>(() => client.Create("owner", "name", 1, null));

                Assert.Throws<ArgumentNullException>(() => client.Create(1, 1, null));

                Assert.Throws<ArgumentException>(() => client.Create("", "name", 1, comment));
                Assert.Throws<ArgumentException>(() => client.Create("owner", "", 1, comment));
            }
            public void PostsToCorrectUrlWithRepositoryId()
            {
                var gitHubClient = Substitute.For<IGitHubClient>();
                var client = new ObservablePullRequestReviewCommentsClient(gitHubClient);

                var comment = new PullRequestReviewCommentCreate("Comment content", "qe3dsdsf6", "file.css", 7);

                client.Create(1, 13, comment);

                gitHubClient.PullRequest.ReviewComment.Received().Create(1, 13, comment);
            }