prow/errorutil/aggregate.go
func (agg aggregate) Strings() []string {
	strs := make([]string, 0, len(agg))
	for _, e := range agg {
		if subAgg, ok := e.(aggregate); ok {
			strs = append(strs, subAgg.Strings()...)
		} else {
			strs = append(strs, e.Error())
		}
	}
	return strs
}
func (agg aggregate) Strings() []string {
	strs := make([]string, 0, len(agg))
	for _, e := range agg {
		if subAgg, ok := e.(aggregate); ok {
			strs = append(strs, subAgg.Strings()...)
		} else {
			strs = append(strs, e.Error())
		}
	}
	return strs
}
// Strings flattens the aggregate (and any sub aggregates) into a
// slice of strings.