}
	t.nextExtra++
	id := t.nextExtra
	t.extraStrings = append(t.extraStrings, s)
	t.extraStringIDs[s] = id
	return id
}

// getExtraString returns the extra string for the provided ID.
// The ID must have been produced by addExtraString for this evTable.
func (t *evTable) getExtraString(id extraStringID) string {
	if id == 0 {
		return ""
	}
	return t.extraStrings[id-1]
}

// dataTable is a mapping from EIs to Es.

	case go122.EvUserTaskBegin:
		parentID = TaskID(e.base.args[1])
		typ = e.table.strings.mustGet(stringID(e.base.args[2]))
	case go122.EvUserTaskEnd:
		parentID = TaskID(e.base.extra(version.Go122)[0])
		typ = e.table.getExtraString(extraStringID(e.base.extra(version.Go122)[1]))
	default:
		panic(fmt.Sprintf("internal error: unexpected event type for Task kind: %s", go122.EventString(e.base.typ)))
	}
	return Task{