diff --git a/contracts/senders/aave-v2-migrator/helpers.sol b/contracts/senders/aave-v2-migrator/helpers.sol
index f078c53..4a720ac 100644
--- a/contracts/senders/aave-v2-migrator/helpers.sol
+++ b/contracts/senders/aave-v2-migrator/helpers.sol
@@ -22,33 +22,6 @@ import {
 abstract contract Helpers is DSMath, Stores, Variables {
     using SafeERC20 for IERC20;
 
-    /**
-     * @dev Aave reserve configuration bit masks
-     */
-    // uint256 constant LIQUIDATION_THRESHOLD_MASK = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF0000FFFF;
-    // uint256 constant DECIMALS_MASK = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00FFFFFFFFFFFF;
-    // uint256 constant LIQUIDATION_THRESHOLD_START_BIT_POSITION = 16;
-    // uint256 constant RESERVE_DECIMALS_START_BIT_POSITION = 48;
-
-    // /**
-    //  * @dev Additional math helpers
-    //  */
-    // uint256 constant PERCENTAGE_FACTOR = 1e4; //percentage plus two decimals
-    // uint256 constant HALF_PERCENT = PERCENTAGE_FACTOR / 2;
-
-    // function percentMul(uint256 value, uint256 percentage) internal pure returns (uint256) {
-    //     if (value == 0 || percentage == 0) {
-    //         return 0;
-    //     }
-
-    //     require(
-    //         value <= (type(uint256).max - HALF_PERCENT) / percentage,
-    //         "percent-mul-overflow"
-    //     );
-
-    //     return (value * percentage + HALF_PERCENT) / PERCENTAGE_FACTOR;
-    // }
-
     function _paybackBehalfOne(AaveInterface aave, address token, uint amt, uint rateMode, address user) private {
         address _token = token == ethAddr ? wethAddr : token;
         aave.repay(_token, amt, rateMode, user);
@@ -127,13 +100,6 @@ abstract contract Helpers is DSMath, Stores, Variables {
         }
     }
 
-    // function _getParams(uint config) internal returns (
-    //     uint liqudationThreshold, uint decimals
-    // ) {
-    //     liqudationThreshold = (config & ~LIQUIDATION_THRESHOLD_MASK) >> LIQUIDATION_THRESHOLD_START_BIT_POSITION;
-    //     decimals = (config & ~DECIMALS_MASK) >> RESERVE_DECIMALS_START_BIT_POSITION;
-    // }
-
     function isPositionSafe() internal returns (bool isOk) {
         AaveInterface aave = AaveInterface(aaveProvider.getLendingPool());
         (,,,,,uint healthFactor) = aave.getUserAccountData(address(this));
@@ -153,7 +119,7 @@ abstract contract Helpers is DSMath, Stores, Variables {
         }
     }
 
-    function convertTo18(uint amount, uint decimal) internal view returns (uint) {
+    function convertTo18(uint amount, uint decimal) internal pure returns (uint) {
         return amount * (10 ** (18 - decimal)); // TODO: verify this
     }
 
@@ -161,7 +127,6 @@ abstract contract Helpers is DSMath, Stores, Variables {
     /*
      * Checks the position to migrate should have a safe gap from liquidation 
     */
-    // TODO: which checkRatio to use?
     function _checkRatio(AaveData memory data) public {
         uint[] memory supplyTokenPrices = getTokensPrices(data.supplyTokens);
         (uint[] memory supplyDecimals, uint[] memory supplyLts) = getTokenLt(data.supplyTokens);
@@ -184,37 +149,4 @@ abstract contract Helpers is DSMath, Stores, Variables {
         require(netBorrow < sub(liquidation, _dif), "position-is-risky-to-migrate");
     }
 
-    // function _checkRatio(AaveData memory data) public returns (bool isOk) {
-    //     uint totalCollateral;
-    //     uint totalDebt;
-    //     uint avgLiquidationThresold;
-
-    //     for(uint i = 0; i < data.supplyTokens.length; i++) {
-    //         address _token = data.supplyTokens[i] == ethAddr ? wethAddr : data.supplyTokens[i];
-    //         ReserveConfigurationMap memory config = aave.getConfiguration(_token);
-    //         (uint _liq, uint _dec) = _getParams(config.data);
-    //         uint assetPrice = aaveOracle.getAssetPrice(_token);
-    //         uint collateral = div(mul(assetPrice, data.supplyAmts[i]), 10**_dec);
-    //         totalCollateral += collateral;
-    //         avgLiquidationThresold += mul(collateral, _liq);
-    //     }
-
-    //     for(uint i = 0; data.borrowTokens.length; i++) {
-    //         address _token = data.supplyTokens[i] == ethAddr ? wethAddr : data.supplyTokens[i];
-    //         ReserveConfigurationMap memory config = aave.getConfiguration(_token);
-    //         (, uint _dec) = _getParams(config.data);
-    //         uint assetPrice = aaveOracle.getAssetPrice(_token);
-    //         uint debt = div(mul(assetPrice, data.borrowAmts[i]), 10**_dec);
-    //         totalDebt += debt;
-    //     }
-
-    //     if (totalCollateral > 0) {
-    //         avgLiquidationThresold = div(avgLiquidationThresold, totalCollateral);
-    //     }
-
-    //     uint healthFactor = wdiv(percentMul(totalCollateral, avgLiquidationThresold), totalDebt);
-    //     uint minLimit = wdiv(1e18, safeRatioGap);
-    //     isOk = healthFactor > minLimit;
-    //     require(isOk, "position-at-risk");
-    // }
 }
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