anchor.diff:        RepositorySlug slug, int number, CreatePullRequestComment comment) {
       return _github.postJSON('/repos/${slug.fullName}/pulls/${number}/comments',
           body: comment.toJSON(),
  -        convert: IssueComment.fromJSON,
  +        convert: PullRequestComment.fromJSON,
           statusCode: 201);
     }
   
  
positive.code:     return _github.postJSON("/repos/${slug.fullName}/pulls",
          convert: PullRequestInformation.fromJSON, body: request.toJSON());
    }
  
    // TODO: implement edit: https://developer.github.com/v3/pulls/#update-a-pull-request
  
    /// Edit a pull request.
    ///
  
negative.code:   /// Lists all comments on the specified pull request.
    ///
    /// API docs: https://developer.github.com/v3/pulls/comments/#list-comments-on-a-pull-request
    Stream<PullRequestComment> listCommentsByPullRequest(
        RepositorySlug slug, int number) {
      return new PaginationHelper(_github).objects("GET",
          "/repos/${slug.fullName}/pulls/${number}/comments",
          PullRequestComment.fromJSON);
    }
  
    /// Lists all comments on all pull requests for the repository.
    ///
    /// API docs: https://developer.github.com/v3/pulls/comments/#list-comments-in-a-repository
    Stream<PullRequestComment> listComments(RepositorySlug slug) {
      return new PaginationHelper(_github).objects(
          "GET", "/repos/${slug.fullName}/pulls/comments", PullRequestComment.fromJSON);
    }
    
    /// Creates a new pull request comment.
    ///
    /// API docs: https://developer.github.com/v3/pulls/comments/#create-a-comment
  