// Basic state transition validation.
			id := tr.Resource.Goroutine()
			old, new := tr.Goroutine()
			if new == trace.GoUndetermined {
				e.Errorf("transition to undetermined state for goroutine %d", id)
			}
			if v.seenSync && old == trace.GoUndetermined {
				e.Errorf("undetermined goroutine %d after first global sync", id)
			}
			if new == trace.GoNotExist && v.hasAnyRange(trace.MakeResourceID(id)) {

				t.Errorf("found region start event for the wrong resource: wanted goroutine %d, got %s", goid, st.Resource)
			}
			if old, _ := st.Goroutine(); old != trace.GoNotExist && old != trace.GoUndetermined {
				t.Errorf("expected transition from GoNotExist or GoUndetermined, got transition from %s instead", old)
			}
		}
	default:
		t.Errorf("unexpected want start event type: %s", wantStart)
	}

	switch wantEnd {
	case trace.EventBad:

				break
			}

			// Handle transition out.
			g := s.gs[id]
			switch old {
			case GoUndetermined, GoNotExist:
				g = &GoroutineSummary{ID: id, goroutineSummary: &goroutineSummary{}}
				// If we're coming out of GoUndetermined, then the creation time is the
				// time of the last sync.
				if old == GoUndetermined {
					g.CreationTime = s.syncTs
				} else {
					g.CreationTime = ev.Time()
				}