Feature request from zbych, posted on GitHub Apr 05, 2015
Getting following error:
Instance of Magento\Framework\Data\CollectionDataSourceInterface is expected, got Some\Backend\Class\Of\Model\Defined\ByMe instead.
I am not sure if it is intended, if it is, and it is within the rules of core functionality, then please cancel this issue and sorry for bothering.
I am just not sure if blocks can accept only objects that inherits the Collection interface.