def get_pulls_review_comments(self, sort=github.GithubObject.NotSet, direction=github.GithubObject.NotSet, since=github.GithubObject.NotSet):
        """
        :calls: `GET /repos/:owner/:repo/pulls/comments <http://developer.github.com/v3/pulls/comments>`_
        :param sort: string
        :param direction: string
        :param since: datetime.datetime
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.PullRequestComment.PullRequestComment`
        """
        assert sort is github.GithubObject.NotSet or isinstance(sort, (str, unicode)), sort
        assert direction is github.GithubObject.NotSet or isinstance(direction, (str, unicode)), direction
        assert since is github.GithubObject.NotSet or isinstance(since, datetime.datetime), since
        url_parameters = dict()
        if sort is not github.GithubObject.NotSet:
            url_parameters["sort"] = sort
        if direction is not github.GithubObject.NotSet:
            url_parameters["direction"] = direction
        if since is not github.GithubObject.NotSet:
            url_parameters["since"] = since.strftime("%Y-%m-%dT%H:%M:%SZ")
        return github.PaginatedList.PaginatedList(
            github.IssueComment.IssueComment,
            self._requester,
            self.url + "/pulls/comments",
            url_parameters
        )