code: def nice(self, work_spec_name, nice):
          '''Change the priority of an existing work spec.'''
          with self.registry.lock(identifier=self.worker_id) as session:
              session.update(NICE_LEVELS, dict(work_spec_name=nice)f nice(self, work_spec_name, nice):
          '''Change the priority of an existing work spec.'''
          with self.registry.lock(identifier=self.worker_id) as session:
              session.update(NICE_LEVELS, dict(work_spec_name=nice))
docs: Change the priority of an existing work spec.