How to create a store

Hey guys,

I found nothing in the wiki or documentation on how to register a store neither how to populate it with a piece.

I do play with the HMR plugin right now and I noticed with some research that only pieces are getting reloaded on change (as intended). So I searched for a way to add my helper classes to the client container as pieces so they get reloaded aswell.

So far I do think that I need to put my helper classes in a store and put them into this store but I didn't found anything related to register a store so maybe you smart guys can help me out by explaining or providing any source of tutorial for me how to do so