@Test
    void verifyEmptyPayload() throws Throwable {
        val data = "{ \"keys\": [] }";
        val keystoreFile = getKeystoreFile();
        try (val webServer = new MockWebServer(data);
             val cipher = new JsonWebKeySetStringCipherExecutor(keystoreFile, "http://localhost:" + webServer.getPort())) {
            webServer.start();
            assertThrows(IllegalArgumentException.class, () -> cipher.encode(UUID.randomUUID().toString()));
        }
    }
This is {@link JsonWebKeySetStringCipherExecutorTests}.

@author Misagh Moayyed
@since 5.3.0
core/cas-server-core-util/src/test/java/org/apereo/cas/util/cipher/JsonWebKeySetStringCipherExecutorTests.java