etcdserver/api/v2v3/store.go
func prevKeyFromPuts(resp *clientv3.TxnResponse) *mvccpb.KeyValue {
	for _, r := range resp.Responses {
		pkv := r.GetResponsePut().PrevKv
		if pkv != nil && pkv.CreateRevision > 0 {
			return pkv
		}
	}
	return nil
}
func prevKeyFromPuts(resp *clientv3.TxnResponse) *mvccpb.KeyValue {
	for _, r := range resp.Responses {
		pkv := r.GetResponsePut().PrevKv
		if pkv != nil && pkv.CreateRevision > 0 {
			return pkv
		}
	}
	return nil
}
func prevKeyFromPuts ( resp * clientv3 . TxnResponse ) * mvccpb . KeyValue { for _ , r := range resp . Responses { pkv := r . GetResponsePut ( ) . PrevKv if pkv != nil && pkv . CreateRevision > 0 { return pkv } } return nil }
// prevKeyFromPuts gets the prev key that is being put; ignores
// the put action response.
prevKeyFromPuts gets the prev key that is being put ; ignores the put action response .