code: func CommonNamesFromCertPool(p *x509.CertPool) ([]string, error) {
  	var names []string
  	for _, rawSubj := range p.Subjects() {
  		n, err := PKIXNameFromRawSubject(rawSubj)
  		if err != nil {
  			return nil, err
  		}
  		names = append(names, n.CommonName)
  	}
  	return names, nil
  }
docs: // CommonNamesFromCertPool returns the common names of the certificates in the
  // cert pool.