docs: public static IterationBuilderOver over(Class<? extends WindupVertexFrame> sourceType, String source)
      {
          Iteration iterationImpl = new Iteration(new TypedNamedFramesSelector(sourceType, source));
          iterationImpl.setPayloadManager(new TypedNamedIterationPayloadManager(sourceType,
                      singleVariableIterationName(source)));
          return iterationImpl;
      }