private static void disallow(HttpRequest request, String... properties) {
        for (String property : properties)
            if (request.parameters().containsKey(property))
                throw new IllegalArgumentException("May not specify '" + property + "' at '" + request.getUri().getRawPath() + "'");
    }
Returns the last property with the given name, if present, or throws if this is empty or blank.
vespaclient-container-plugin/src/main/java/com/yahoo/document/restapi/resource/DocumentV1ApiHandler.java