Two peculiarities with Rails.cache.fetch()

Hi,

I'm experimenting with using this inside of models which provide
mostly static data from the database.

However, both cases where I wanted to use it, it seems to not work;
I'm not sure if it's me, or the library:

1) To save a boolean value. For example:

  Rails.cache.fetch("#{cache_key}.has_children")
{ self.has_children? }

In the case of a 'false' result, this seems to always result in a
cache miss the next time. I'm guessin that the logic of fetch() is
such that it tests for success, not simply for "nil"?

2) To save ActiveRecords. I find that upon pulling them out of the
cache, they don't behave as expected. IOW, some methods aren't found.

Thanks for any input,
Robb