func createHeadersFilter(filter *k8s.HTTPHeaderFilter) *istio.Headers_HeaderOperations {
	if filter == nil {
		return nil
	}
	return &istio.Headers_HeaderOperations{
		Add:    headerListToMap(filter.Add),
		Remove: filter.Remove,
		Set:    headerListToMap(filter.Set),
	}
}

// nolint: unparam
func createMethodMatch(match k8s.HTTPRouteMatch) (*istio.StringMatch, *ConfigError) {
	if match.Method == nil {