@Override
    public List<ParamInfo> getParamInfo() {
        return List.of(
                ParamInfo.optionalParam(PARAM_NAME_LIMIT,
                        "A limit on the number of keys to return, default is unlimited."),
                ParamInfo.optionalParam(PARAM_NAME_CACHE_NAME,
                        "The name of the cache to see the list of keys for. " +
                        "If not supplied a list of cache names will be returned"));
    }
This is only for tests to save providing a {@link Metrics} instance
stroom-cache/stroom-cache-impl/src/main/java/stroom/cache/impl/CacheManagerImpl.java