assertTrue(fieldConfigs.getConfig("test").isEmpty());
        assertFalse(fieldConfigs.getConfig("foo").isEmpty());
        assertFalse(fieldConfigs.getConfig("foo").map(FieldConfigs.Config::isCache).orElse(false));
        assertFalse(fieldConfigs.getConfig("foo").map(FieldConfigs.Config::isOverwrite).orElse(false));

         * for backward compatibility.
         *
         * @return true if caching is enabled, false otherwise
         */
        public boolean isCache() {
            for (final String value : values) {
                if ("cache".equalsIgnoreCase(value)) {
                    return true;
                }
            }
            // backward compatibility