if (cycle != null) {
            // remove edge which introduced cycle
            removeEdge(from, to);
            throw new CycleDetectedException(
                    "Edge between '" + from.label + "' and '" + to.label + "' introduces to cycle in the graph", cycle);
        }
    }

    void removeEdge(Vertex from, Vertex to) {
        from.children.remove(to);
        to.parents.remove(from);
    }

          back_edges_.push_back(
              BackEdge{e, e->src(), e->src_output(), e->dst(), e->dst_input()});
        }
      }
    }
  }
  for (const BackEdge& be : back_edges_) {
    graph_->RemoveEdge(be.edge);
  }
  return absl::OkStatus();
}

const std::vector<BackEdgeHelper::BackEdge>& BackEdgeHelper::RemovedEdges()
    const {
  return back_edges_;
}

Status BackEdgeHelper::Replace() {

        TF_RET_CHECK(e->src_output() == 0)
            << "expected constant to have exactly one non-control output, but "
               "found output index = "
            << e->src_output();
        graph_->RemoveEdge(e);
        graph_->AddEdge(input_cloned, 0, n, dst_input);
      }
    }
  }
  return absl::OkStatus();
}

Status CloneConstantsForBetterClusteringPassImpl::Run() {