code: public @Nullable <K, V> CacheProxy<K, V> tryToCreateFromExternalSettings(String cacheName) {
      Optional<CaffeineConfiguration<K, V>> configuration =
          TypesafeConfigurator.from(rootConfig, cacheName);
      return configuration.isPresent() ? createCache(cacheName, configuration.get()) : null;
    }
docs: Returns a newly created cache instance if a definition is found in the external settings file.
  
  @param cacheName the name of the cache
  @return a new cache instance or null if the named cache is not defined in the settings file