func (a *AsPathPrependAction) apply(path *table.Path) *table.Path { var asn uint32 if a.useLeftMost { asns := path.GetAsSeqList() if len(asns) == 0 { log.WithFields(log.Fields{ "Topic": "Policy", "Type": "AsPathPrepend Action", }).Error("aspath length is zero.") return path } asn = asns[0] log.WithFields(log.Fields{ "Topic": "Policy", "Type": "AsPathPrepend Action", "LastAs": asn, "Repeat": a.repeat, }).Debug("use last AS.") } else { asn = a.asn } path.PrependAsn(asn, a.repeat) return path }