};

// Matches a dst and dst_output on an input edge.  Today we only use this with
// dst_output=0 but we will eventually need to support multi-output operations.
class OutEdgeMatcher : public ::testing::MatcherInterface<OutEdge> {
 public:
  OutEdgeMatcher(::testing::Matcher<const Node*> src_matcher, int src_oidx)
      : src_matcher_(std::move(src_matcher)), src_oidx_(src_oidx) {}

  bool MatchAndExplain(
      OutEdge out_edge,