interface IPriceProvider {
    // pair - uniswap address
    // base - erc20 contract as base currency
    // return price with 18 decimals precision
    function getPairPrice(address pair, address base)
        external
        view
        returns (uint256);
}
function getPairPrice(address pair, address base)
    external
    view
    returns (uint256);

// pair - uniswap address
// base - erc20 contract as base currency
// return price with 18 decimals precision