event PairCreated(address token0, address token1, address pair, uint256)
function feeTo() external view returns (address)
function feeToSetter() external view returns (address)
function migrator() external view returns (address)
function getPair(address tokenA, address tokenB) external view returns (address pair)
function allPairs(uint256) external view returns (address pair)
function allPairsLength() external view returns (uint256)
function createPair(address tokenA, address tokenB) external returns (address pair)
function setFeeTo(address) external
function setFeeToSetter(address) external
function setMigrator(address) external