Preserve traversing over null instead of empty array when no transactions are appended

[brabijan]

No description provided.

[brabijan]

@h4kuna how can i generate new version of 2011-01-01-2011-01-02-transactions.srlz? i want to fix test

[h4kuna]

Thank you, I do it. And file is generate like

Test\Utils::saveFile('2011-01-01-2011-01-02-transactions.srlz', serialize($data));

This commit

[brabijan]

i tried that this way, but test weren't passed... whatever, thanks for merge :-)