@Test
    void verifyEmptyFileForEncoding() throws Throwable {
        val keystoreFile = File.createTempFile("keystore", ".json");
        FileUtils.write(keystoreFile, "{ \"keys\": [] }", StandardCharsets.UTF_8);
        try (val cipher = new JsonWebKeySetStringCipherExecutor(keystoreFile)) {
            assertThrows(IllegalArgumentException.class, () -> cipher.encode("value", EMPTY_OBJECT_ARRAY));
        }
    }
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