Gearbox swap

swap.sol

 // store balances before swap
  uint256 balanceInBefore = _vaultService.getBalance(tokenIn);
  uint256 balanceOutBefore = _vaultService.getBalance(tokenOut);

  // swapTokens
  _vaultService.swapTokensForExactTokens(
       amountOut,
       amountInMax,
      path,
      deadline
  );

  // compute changes in balances
  uint256 amountInSpent =
      balanceInBefore.sub(_vaultService.getBalance(tokenIn));
  uint256 amountOutGot =
      _vaultService.getBalance(tokenOut).sub(balanceOutBefore);

  // update stored balances with differences
  _PositionRepository.swapAssets(
      msg.sender,
      tokenIn,
      amountInSpent,
      tokenOut,
      amountOutGot
  );