code: func (c *ca) NewServerCertKeyPair(host string) (*CertKeyPair, error) {
  	keypair, err := newCertKeyPair(false, true, host, c.caCert.Signer, c.caCert.TLSCert)
  	if err != nil {
  		return nil, err
  	}
  	return keypair, nil
  }
docs: // newServerCertKeyPair returns a certificate and private key pair and nil,
  // or nil, error in case of failure
  // The certificate is signed by the CA and is used as a server TLS certificate