code: def pending_work_items(self):
          "Iterable of all pending work items."
          pending = self._conn.execute(
              "SELECT * FROM work_items WHERE job_id NOT IN (SELECT job_id FROM results)"
          )
          return (_row_to_work_item(p) for p in pendingf pending_work_items(self):
          "Iterable of all pending work items."
          pending = self._conn.execute(
              "SELECT * FROM work_items WHERE job_id NOT IN (SELECT job_id FROM results)"
          )
          return (_row_to_work_item(p) for p in pending)
docs: Iterable of all pending work items.