code: func (idp *IDP) downloadConsentKey() (*rsa.PrivateKey, error) {
  	jwk, err := idp.hc.JSONWebKeys.GetKey(hoauth2.ConsentEndpointKey, "private")
  	if err != nil {
  		return nil, err
  	}
  
  	rsaKey, ok := hjwk.First(jwk.Keys).Key.(*rsa.PrivateKey)
  	if !ok {
  		return nil, ErrorBadPrivateKey
  	}
  
  	return rsaKey, nil
  }
docs: // Downloads the private key used for signing the consent