private SSLContext resolveSSLContext() {
        if (!isHttps(tokenEndpointUri)) {
            return null;
        }
        return sslContextSupplier == null ? null : sslContextSupplier.get();
    }

    private HttpURLConnection openConnection() throws IOException {
        log.debugf("Opening connection to [%s]", tokenEndpointUri);
        HttpURLConnection connection = (HttpURLConnection) tokenEndpointUri.openConnection();

        if (isHttps(tokenEndpointUri)) {
            HttpsURLConnection https = (HttpsURLConnection) connection;

            https.setSSLSocketFactory(resolveSSLContext().getSocketFactory());
            if (hostnameVerifierSupplier != null) {
                https.setHostnameVerifier(checkNotNullParam("hostnameVerifier", hostnameVerifierSupplier.get()));
            }
        }

        return connection;
    }