public List<Short> allVersions() {
        List<Short> versions = new ArrayList<>(latestVersion() - oldestVersion() + 1);
        for (short version = oldestVersion(); version <= latestVersion(); version++) {
            versions.add(version);
        }
        return versions;
    }
indicates whether the API is enabled for forwarding
clients/src/main/java/org/apache/kafka/common/protocol/ApiKeys.java