Commission Implementing Regulation (EU) 2021/2157 of 6 December 2021 initiating a review of Implementing Regulations (EU) 2021/1266 and (EU) 2021/1267 extending, respectively, the definitive anti-dumping and countervailing duty on imports of biodiesel consigned from Canada, whether declared as originating in Canada or not, for the purposes of determining the possibility of granting an exemption from those measures to one Canadian exporting producer, repealing the anti-dumping duty with regard to imports from that exporting producer and making imports from that exporting producer subject to registration