private static Stream<String> encodeMultiParameter(final String key, final String[] values, final String encoding) {
        return Stream.of(values).map(value -> encodeSingleParameter(key, value, encoding));
    }
Default flow execution key parameter name, {@value}.
Same as that used by {@link DefaultFlowUrlHandler}.
core/cas-server-core-webflow-api/src/main/java/org/apereo/cas/web/flow/CasDefaultFlowUrlHandler.java