Compile error when calling mycluster.Authenticate(gocb.CertificateAuthenticator{}) in gocbcv14 repo

For testing traceability and compression feature, I'm using gocbv14 repo.
With the same code, when I try to test client certificate, I call

mycluster.Authenticate(gocb.CertificateAuthenticator{})

and this spews compile error complaining gocb.CertificateAuthenticator{} is not Authenticator interface type.
Looking at the code I found https://github.com/couchbaselabs/gocbv14/blob/master/auth.go#L59 defines interface returns ([]UserPassPair, error) while https://github.com/couchbaselabs/gocbv14/blob/master/auth.go#L134 returns ([]gocbcore.UserPassPair, error) which means CertificateAuthenticator struct does not implement Credentials function for Athenticator interface