fix DVM test

contracts/DODOVendingMachine/impl/DVMStorage.sol

@@ -88,4 +88,14 @@ contract DVMStorage is InitializableOwnable, ReentrancyGuard {
     function setSell(bool open) external onlyOwner {
         _SELLING_CLOSE_ = !open;
     }
+
+    // ============ View Functions ============
+
+    function getLpFeeRate(address trader) external view returns (uint256 feeRate) {
+        return _LP_FEE_RATE_MODEL_.getFeeRate(trader);
+    }
+
+    function getMtFeeRate(address trader) external view returns (uint256 feeRate) {
+        return _MT_FEE_RATE_MODEL_.getFeeRate(trader);
+    }
 }

contracts/lib/DODOMath.sol

@@ -52,8 +52,8 @@ library DODOMath {
         c=-kQ0^2
         and Q2=(-b+sqrt(b^2+4(1-k)kQ0^2))/2(1-k)
         note: another root is negative, abondan
-        if deltaBSig=true, then Q2>Q1
-        if deltaBSig=false, then Q2<Q1
+        if deltaBSig=true, then Q2>Q1, user sell Q and receive B
+        if deltaBSig=false, then Q2<Q1, user sell B and receive Q
         return |Q1-Q2|
     */
     function _SolveQuadraticFunctionForTrade(

contracts/lib/PMMPricing.sol

@@ -207,7 +207,7 @@ library PMMPricing {
                 state.B,
                 DecimalMath.divFloor(payQuoteAmount, state.i),
                 false,
-                state.i
+                state.K
             );
     }