// on. `return_nodes` are nodes in `src_graph`, and the new corresponding nodes
// in `dst_graph` will be returned. `return_nodes` must be non-null.
Status CopyGraph(Graph* src_graph, Graph* dst_graph,
                 tensorflow::ShapeRefiner* dst_refiner,
                 const TF_Output* src_inputs,
                 const std::vector<tensorflow::Output>& dst_inputs,