diff --git a/contracts/tool/BSCValidatorSetTool.sol b/contracts/extension/BSCValidatorSetTool.sol
similarity index 100%
rename from contracts/tool/BSCValidatorSetTool.sol
rename to contracts/extension/BSCValidatorSetTool.sol
diff --git a/contracts/mock/MockTokenHub.sol b/contracts/mock/MockTokenHub.sol
deleted file mode 100644
index 09e36375..00000000
--- a/contracts/mock/MockTokenHub.sol
+++ /dev/null
@@ -1,66 +0,0 @@
-pragma solidity 0.6.4;
-
-import "../interface/0.6.x/ITokenHub.sol";
-
-contract MockTokenHub is ITokenHub {
-    bool panicBatchTransferOut;
-
-    bytes32 public constant BEP2_TOKEN_SYMBOL_FOR_BNB =
-        0x424E420000000000000000000000000000000000000000000000000000000000; // "BNB"
-
-    function getMiniRelayFee() external view override(ITokenHub) returns (uint256) {
-        return (1e16);
-    }
-
-    function getContractAddrByBEP2Symbol(bytes32) external view override(ITokenHub) returns (address) {
-        return address(0x0);
-    }
-
-    function getBep2SymbolByContractAddr(address) external view override(ITokenHub) returns (bytes32) {
-        return bytes32(0x0);
-    }
-
-    function bindToken(bytes32 bep2Symbol, address contractAddr, uint256 decimals) external override(ITokenHub) { }
-
-    function unbindToken(bytes32 bep2Symbol, address contractAddr) external override(ITokenHub) { }
-
-    function recoverBCAsset(bytes32, address, uint256) external override(ITokenHub) { }
-
-    function cancelTokenRecoverLock(bytes32, address) external override {
-        address TOKEN_RECOVER_PORTAL_ADDR = address(0x0000000000000000000000000000000000003000);
-        require(msg.sender == TOKEN_RECOVER_PORTAL_ADDR, "only token reover portal contract can call this function");
-    }
-
-    function transferOut(address, address, uint256, uint64) external payable override(ITokenHub) returns (bool) {
-        return true;
-    }
-
-    /* solium-disable-next-line */
-    function batchTransferOutBNB(
-        address[] calldata,
-        uint256[] calldata,
-        address[] calldata,
-        uint64
-    ) external payable override(ITokenHub) returns (bool) {
-        require(!panicBatchTransferOut, "panic in batchTransferOut");
-        return true;
-    }
-
-    function setPanicBatchTransferOut(bool doPanic) external {
-        panicBatchTransferOut = doPanic;
-    }
-
-    function withdrawStakingBNB(uint256 amount) external override returns (bool) {
-        address STAKING_CONTRACT_ADDR = address(0x0000000000000000000000000000000000002001);
-        require(msg.sender == STAKING_CONTRACT_ADDR, "only staking system contract can call this function");
-        if (amount != 0) {
-            payable(STAKING_CONTRACT_ADDR).transfer(amount);
-        }
-        return true;
-    }
-
-    function cancelTransferIn(address, address) external override {
-        address CROSS_CHAIN_CONTRACT_ADDR = address(0x0000000000000000000000000000000000002000);
-        require(msg.sender == CROSS_CHAIN_CONTRACT_ADDR, "only cross chain contract can call this function");
-    }
-}