docs: static boolean isClassificationLinkedToFileModel(GraphRewrite event, ClassificationModel classificationModel, FileModel fileModel)
      {
          String key = getClassificationFileModelCacheKey(classificationModel, fileModel);
          Boolean linked = getCache(event).get(key);
  
          if (linked == null)
          {
              GraphTraversal<Vertex, Vertex> existenceCheck = new GraphTraversalSource(event.getGraphContext().getGraph()).V(classificationModel.getElement());
              existenceCheck.out(ClassificationModel.FILE_MODEL);
              existenceCheck.filter(vertexTraverser -> vertexTraverser.get().equals(fileModel.getElement()));
  
              linked = existenceCheck.hasNext();
              cacheClassificationFileModel(event, classificationModel, fileModel, linked);
          }
          return linked;
      }