Question: I am new with zarr, HDF5 and LMDB. I have converted data from HDF5 to Zarr but i got many files with extension .n (n from 0 to 31). I want to have just one file with .zarr extension. I tried to use LMDB (zarr.LMDBStore function) but i don't understand how to create .mdb file ? Do you have an idea how to do that ? 
Thank you !

Answer: 
According to karate docs you have to use `callonce`

> 
> Variables set using def in the Background will be re-set before every Scenario. If you are looking for a way to do something only once
>  per Feature, take a look at callonce. On the other hand, if you are
>  expecting a variable in the Background to be modified by one Scenario
>  so that later ones can see the updated value - that is not how you
>  should think of them, and you should combine your 'flow' into one
>  scenario. Keep in mind that you should be able to comment-out a
>  Scenario or skip some via tags without impacting any others. Note that
>  the parallel runner will run Scenario-s in parallel, which means they
>  can run in any order.
> 
> 
> 

Please check 

* <https://github.com/intuit/karate#script-structure>
* <https://github.com/intuit/karate#callonce>
* <https://github.com/intuit/karate/blob/master/karate-demo/src/test/java/demo/callonce/call-once.feature>
Background:

* karate.callSingle('called.feature@scenarioToBeCalledOnceInBackground');