return delegate().hasEdgeConnecting(transpose(endpoints));
    }
  }

  // NOTE: this should work as long as the delegate graph's implementation of edges() (like that of
  // AbstractValueGraph) derives its behavior from calling successors().
  private static final class TransposedValueGraph<N, V> extends ForwardingValueGraph<N, V> {
    private final ValueGraph<N, V> graph;

      return delegate().hasEdgeConnecting(transpose(endpoints));
    }
  }

  // NOTE: this should work as long as the delegate graph's implementation of edges() (like that of
  // AbstractValueGraph) derives its behavior from calling successors().
  private static final class TransposedValueGraph<N, V> extends ForwardingValueGraph<N, V> {
    private final ValueGraph<N, V> graph;