Empty optional nested array

[ipkes]

Based on issue and tests

1. Some test modification
2. Possible solution

[ipkes]

I'm afraid solution is insufficient and needs some work here. A major problem here with digging deeper in array. Need more time to think

[dblock]

Start by rebasing and squashing this, there're a bunch of unrelated changes, hard to grok.

[ipkes]

1. correctly done rebasing
2. another spec modify, more complex example (to digging deeper)
3. and sufficient solution

   ---

   problem was with checking on blank, first sometimes we have already blank parameter and we should check it and second we should check on blank not for all elements, just for any.

[ipkes]

And for information. When I tried to find solution, I analyzed elements and parameters, which came, without complete understanding why they are coming. I can't be sure that anything else parameters will be work as well, but to already described parameters, it's ok.

[dblock]

This makes total sense to me. We want to do an allow_blank validation if anything is blank here. Merging.

[dblock]

Merged via 9a08358, thank you.