public void refresh(final OidcCredentials credentials) {
        val refreshToken = credentials.toRefreshToken();
        if (refreshToken != null) {
            try {
                val request = createTokenRequest(new RefreshTokenGrant(refreshToken));
                executeTokenRequest(request, credentials);
            } catch (final IOException | ParseException e) {
                throw new OidcException(e);
            }
        }
    }
<p>refresh.</p>

@param credentials a {@link OidcCredentials} object
pac4j-oidc/src/main/java/org/pac4j/oidc/credentials/authenticator/OidcAuthenticator.java