public bool Invalidate(IPipelineStage stage)
 {
     if (Invalidated.Add(stage))
     {
         InvalidatedByThisStep.Add(stage);
         return(true);
     }
     return(false);
 }
 public void PrepareForNextStage(List <IPipelineStage> dependent)
 {
     InvalidatedByThisStep.Clear();
     DependentStages = dependent;
 }