:type status:

        :param user:

        :type user:

        :param comment:

        :type comment:

        :param dont_allow_on_closed_pull_request: don't allow a status change

            if last status was for pull request and it's closed. We shouldn't

            mess around this manually

        """

        repo = self._get_repo(repo)

        q = ChangesetStatus.query()

        if revision:

            q = q.filter(ChangesetStatus.repo == repo)

            q = q.filter(ChangesetStatus.revision == revision)

        elif pull_request:

            pull_request = self.__get_pull_request(pull_request)

            q = q.filter(ChangesetStatus.repo == pull_request.org_repo)

            q = q.filter(ChangesetStatus.pull_request == pull_request)

        cur_statuses = q.all()

        #if statuses exists and last is associated with a closed pull request

        # we need to check if we can allow this status change

            raise StatusChangeOnClosedPullRequestError(

                'Changing status on closed pull request is not allowed'

            )

        if cur_statuses:

            for st in cur_statuses:

                st.version += 1

                self.sa.add(st)

        def _create_status(user, repo, status, comment, revision, pull_request):

            new_status = ChangesetStatus()

            new_status.author = self._get_user(user)

            new_status.repo = self._get_repo(repo)

            new_status.status = status

            new_status.comment = comment

            new_status.revision = revision

            new_status.pull_request = pull_request

            return new_status

        if revision:

            new_status = _create_status(user=user, repo=repo, status=status,

                           comment=comment, revision=revision,

                           pull_request=None)

            self.sa.add(new_status)