function fillOrder(
	Order memory order,
	bytes calldata signature,
	uint256[] memory floorAssetTokenIds
) public payable returns (uint256 positionId) {
	..SNIP..
	// create long/short position for maker
	_mint(order.maker, uint256(orderHash));

	// create opposite long/short position for taker
	bytes32 oppositeOrderHash = hashOppositeOrder(order);
	positionId = uint256(oppositeOrderHash);
	_mint(msg.sender, positionId);
	..SNIP..
