code: public static GraphTraversal<Vertex, Vertex> addPipeFor(GraphTraversal<Vertex, Vertex> pipeline,
                  Class<? extends WindupVertexFrame> clazz)
      {
          pipeline.has(WindupVertexFrame.TYPE_PROP, GraphTypeManager.getTypeValue(clazz));
          return pipeline;
      }
docs: Adds a criterion to given pipeline which filters out vertices representing given WindupVertexFrame.