private SignedRequestHandler createJwtSignedRequestHandler(final InstallHandlerServlet installHandlerServlet) { return (uri, method, username, connection) -> { try { final String sharedSecret = checkNotNull(installHandlerServlet.getInstallPayload().getSharedSecret()); final String jwt = AddonTestUtils.generateJwtSignature(HttpMethod.valueOf(method), uri, addonBuilder.getKey(), sharedSecret, productBaseUrl, null); connection.setRequestProperty("Authorization", "JWT " + jwt); } catch (UnsupportedEncodingException | NoSuchAlgorithmException e) { throw new RuntimeException(e); } }; }