In your docs it is stated that in order the get protection against uncled blocks, the following check should be included in the smart contratc function or transaction:
require(blockhash(block.number - 1) == expectedParentHash, "block was uncled");
My question is: where do I source the expectedParentHash? How can I implement this correctly? As far as I know, expectedParentHash is not a global variable. How can I make my contract find the right one?