func gen(t *testgen.Trace) {
	// A running goroutine emits a task begin.
	t.RawEvent(go122.EvEventBatch, nil, 1 /*gen*/, 0 /*thread ID*/, 0 /*timestamp*/, 5 /*batch length*/)
	t.RawEvent(go122.EvFrequency, nil, 15625000)

	// A running goroutine emits a task begin.
	t.RawEvent(go122.EvEventBatch, nil, 1 /*gen*/, 0 /*thread ID*/, 0 /*timestamp*/, 5 /*batch length*/)
	t.RawEvent(go122.EvGoCreate, nil, 0 /*timestamp delta*/, 1 /*go ID*/, 0, 0)

		}
		b.RawEvent(go122.EvStack, nil, args...)

		// Flush the batch if necessary.
		if !g.ignoreStackBatchSizeLimit && b.size > go122.MaxBatchSize/2 {
			b.writeEventsTo(tw)
			b = g.newStructuralBatch()
		}
	}
	b.writeEventsTo(tw)

	// Write strings.
	b = g.newStructuralBatch()
	b.RawEvent(go122.EvStrings, nil)
	for s, id := range g.strings {
		b.RawEvent(go122.EvString, []byte(s), id)

		Events:        events,
		Stacks:        p.stacks,
		Strings:       p.strings,
		InlineStrings: p.inlineStrings,
		PCs:           p.pcs,
	}
	return res, nil
}

// rawEvent is a helper type used during parsing.
type rawEvent struct {
	typ   event.Type
	args  []uint64
	sargs []string

	// if typ == EvBatch, these fields describe the batch.
	batchPid    int32
	batchOffset int
}