code: def update_artifact_cache(self, vts_artifactfiles_pairs):
      
      update_artifact_cache_work = self._get_update_artifact_cache_work(vts_artifactfiles_pairs)
      if update_artifact_cache_work:
        self.context.submit_background_work_chain([update_artifact_cache_work],
                                                  parent_workunit_name='cache')
docs: Write to the artifact cache, if we're configured to.
  
      vts_artifactfiles_pairs - a list of pairs (vts, artifactfiles) where
        - vts is single VersionedTargetSet.
        - artifactfiles is a list of absolute paths to artifacts for the VersionedTargetSet.