private MaterialRevision materialRevisionForDownstream(
     DependencyMaterial material, Stage upstreamStage) {
   StageIdentifier identifier = upstreamStage.getIdentifier();
   String rev = identifier.getStageLocator();
   String pipelineLabel = identifier.getPipelineLabel();
   return new MaterialRevision(
       material, new Modification(new Date(), rev, pipelineLabel, upstreamStage.getPipelineId()));
 }