code: def get_columns(self):
          
  
          return github.PaginatedList.PaginatedList(
              github.ProjectColumn.ProjectColumn,
              self._requester,
              self.columns_url,
              None,
              {"Accept": Consts.mediaTypeProjectsPreview}
          )
docs: :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`