def get_columns(self):
        """
        :calls: `GET /projects/:project_id/columns <https://developer.github.com/v3/projects/columns/#list-project-columns>`_
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.ProjectColumn.ProjectColumn`
        """

        return github.PaginatedList.PaginatedList(
            github.ProjectColumn.ProjectColumn,
            self._requester,
            self.columns_url,
            None,
            {"Accept": Consts.mediaTypeProjectsPreview}
        )
:calls: `GET /projects/:project_id/columns <https://developer.github.com/v3/projects/columns/#list-project-columns>`_
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.ProjectColumn.ProjectColumn`