code: func WithProcessClosed(ctx context.Context, p goprocess.Process) context.Context {
  	ctx, cancel := context.WithCancel(ctx)
  	go func() {
  		<-p.Closed()
  		cancel()
  	}()
  	return ctx
  }
docs: // WithProcessClosed returns a context.Context that is cancelled
  // after Process p is Closed. It is the equivalent of:
  //
  //   func WithProcessClosed(ctx context.Context, p goprocess.Process) context.Context {
  //     ctx, cancel := context.WithCancel(ctx)
  //     go func() {
  //       <-p.Closed()
  //       cancel()
  //     }()
  //     return ctx
  //   }
  //