started := time.Now()
				dl, _ := ctx.Deadline()
				if testing.Verbose() {
					fmt.Println(GetCaller(ctx).Name, "Server deadline:", time.Until(dl))
				}
				<-ctx.Done()
				serverCanceled <- time.Since(started)
				if testing.Verbose() {
					fmt.Println(GetCaller(ctx).Name, "Server Context canceled with", ctx.Err(), "after", time.Since(started))
				}
				return nil
			},

Sample handler:
```go
    handler :=  func(ctx context.Context, payload []byte, in <-chan []byte, out chan<- []byte) *RemoteErr {
        fmt.Println("Got request with initial payload", p, "from", GetCaller(ctx context.Context))
        fmt.Println("Subroute:", GetSubroute(ctx))
        for {
            select {
            case <-ctx.Done():
                return nil
            case req, ok := <-in:

type RemoteClient struct {
	Name string
}

type (
	ctxCallerKey   = struct{}
	ctxSubrouteKey = struct{}
)

// GetCaller returns caller information from contexts provided to handlers.
func GetCaller(ctx context.Context) *RemoteClient {
	val, _ := ctx.Value(ctxCallerKey{}).(*RemoteClient)
	return val
}

	prog := &obj.Prog{
		Ctxt: p.ctxt,
		Pos:  p.pos(),
		As:   op,
	}
	switch len(a) {
	case 0:
		// Nothing to do.
	case 1:
		if p.arch.UnaryDst[op] || op == obj.ARET || op == obj.AGETCALLERPC {
			// prog.From is no address.
			prog.To = a[0]
		} else {
			prog.From = a[0]
			// prog.To is no address.
		}
		if p.arch.Family == sys.PPC64 && arch.IsPPC64NEG(op) {