Update() public method

Updates a specified Issue Comment.
http://developer.github.com/v3/issues/comments/#edit-a-comment
public Update ( long repositoryId, int id, string commentUpdate ) : Task
repositoryId long The Id of the repository
id int The comment id
commentUpdate string The modified comment
return Task
        public async Task EnsuresArgumentsNotNull()
        {
            var connection = Substitute.For<IApiConnection>();
            var client = new IssueCommentsClient(connection);

            await AssertEx.Throws<ArgumentNullException>(async () => await client.Update(null, "name", 42, "title"));
            await AssertEx.Throws<ArgumentException>(async () => await client.Update("", "name", 42, "x"));
            await AssertEx.Throws<ArgumentNullException>(async () => await client.Update("owner", null, 42, "x"));
            await AssertEx.Throws<ArgumentException>(async () => await client.Update("owner", "", 42, "x"));
            await AssertEx.Throws<ArgumentNullException>(async () => await client.Update("owner", "name", 42, null));
        }
        public void PostsToCorrectUrl()
        {
            const string issueCommentUpdate = "Worthwhile update";
            var connection = Substitute.For<IApiConnection>();
            var client = new IssueCommentsClient(connection);

            client.Update("fake", "repo", 42, issueCommentUpdate);

            connection.Received().Patch<IssueComment>(Arg.Is<Uri>(u => u.ToString() == "repos/fake/repo/issues/comments/42"), Arg.Any<object>());
        }