public static String getString(final Map<String, Object> configs, final String key, final String defaultValue) {
            final Object value = configs.getOrDefault(key, defaultValue);
            if (value instanceof String) {
                return (String) value;
            } else {
                log.warn("Invalid value (" + value + ") on internal configuration '" + key + "'. Please specify a String value.");
                return defaultValue;
            }
        }
{@code topology.optimization}
@deprecated since 2.7; use {@link #TOPOLOGY_OPTIMIZATION_CONFIG} instead
streams/src/main/java/org/apache/kafka/streams/StreamsConfig.java