Nativeextension with your Collection, it becomes your Collection’s unique ERC1155 interface; i.e, an additional ERC1155 interface that is separate to the Main Interface. It acts as a ‘projection’ of your Collection, implementing the
collectionId, along with all other Collections, stored as their
collectionIds. This is a significant change from v1 of the Items protocol, in which Collections were entirely separate contracts from the Main Interface.