code: @SafeVarargs
    public final SpringCache2kCacheManager addCaches(Function<Cache2kBuilder<?,?>, Cache2kBuilder<?,?>>... fs) {
      for (Function<Cache2kBuilder<?,?>, Cache2kBuilder<?,?>> f : fs) {
        addCache(f.apply(defaultSetup.apply(Cache2kBuilder.forUnknownTypes().manager(manager))));
      }
      return this;
    }
docs: Adds a caches to this cache manager that maybe is configured via the {@link Cache2kBuilder}.
  The configuration parameter {@link Cache2kBuilder#exceptionPropagator}
  is managed by this class and cannot be used. This method can be used in case a programmatic
  configuration of a cache manager is preferred.
  
  <p>Rationale: The method provides a builder that is already seeded with the effective manager.
  This makes it possible to use the builder without code bloat. Since the actual build is done
  within this class, it is also possible to reset specific settings or do assertions.
  
  @throws IllegalArgumentException if cache is already created