Combine mixins

6 files changed, 218 insertions, 284 deletions

diff --git a/packages/contracts/src/2.0.0/forwarder/Forwarder.sol b/packages/contracts/src/2.0.0/forwarder/Forwarder.sol
index 38128d93e..0542736a3 100644
--- a/packages/contracts/src/2.0.0/forwarder/Forwarder.sol
+++ b/packages/contracts/src/2.0.0/forwarder/Forwarder.sol
@@ -19,9 +19,8 @@
 pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
-import "./MixinWethFees.sol";
-import "./MixinMarketSellTokens.sol";
-import "./MixinMarketBuyTokens.sol";
+import "./MixinFees.sol";
+import "./MixinForwarderCore.sol";
 import "./MixinConstants.sol";
 import "../utils/Ownable/Ownable.sol";
 
@@ -29,10 +28,9 @@ import "../utils/Ownable/Ownable.sol";
 contract Forwarder is
     Ownable,
     MixinConstants,
-    MixinWethFees,
+    MixinFees,
     MixinMarketBuyZrx,
-    MixinMarketBuyTokens,
-    MixinMarketSellTokens
+    MixinForwarderCore
 {
     uint256 constant internal MAX_UINT = 2**256 - 1;
 
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinERC721.sol b/packages/contracts/src/2.0.0/forwarder/MixinERC721.sol
deleted file mode 100644
index b5be223b6..000000000
--- a/packages/contracts/src/2.0.0/forwarder/MixinERC721.sol
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
-
-  Copyright 2018 ZeroEx Intl.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-*/
-
-pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
-
-import "../utils/LibBytes/LibBytes.sol";
-import "../tokens/ERC721Token/IERC721Token.sol";
-
-
-contract MixinERC721 {
-
-    using LibBytes for bytes;
-
-    bytes4 constant internal ERC721_RECEIVED = bytes4(keccak256("onERC721Received(address,uint256,bytes)"));
-    bytes4 constant internal ERC721_RECEIVED_OPERATOR = bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"));
-
-    function onERC721Received(address, uint256, bytes memory)
-        public
-        pure
-        returns(bytes4)
-    {
-        return ERC721_RECEIVED;
-    }
-
-    function onERC721Received(address, address, uint256, bytes memory)
-        public
-        pure
-        returns(bytes4)
-    {
-        return ERC721_RECEIVED_OPERATOR;
-    }
-
-    function transferERC721Token(
-        bytes memory assetData,
-        address to
-    )
-        internal
-    {
-        // Decode asset data.
-        address token = assetData.readAddress(16);
-        uint256 tokenId = assetData.readUint256(36);
-        bytes memory receiverData = assetData.readBytesWithLength(100);
-        IERC721Token(token).safeTransferFrom(
-            address(this),
-            to,
-            tokenId,
-            receiverData
-        );
-    }
-}
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol b/packages/contracts/src/2.0.0/forwarder/MixinFees.sol
index c8069aa8c..c32658630 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinFees.sol
@@ -22,14 +22,14 @@ import "../protocol/Exchange/libs/LibMath.sol";
 import "./MixinConstants.sol";
 
 
-contract MixinWethFees is
+contract MixinFees is
     LibMath,
     MixinConstants
 {
 
-    uint16  constant public PERCENTAGE_DENOMINATOR = 10000; // 9800 == 98%, 10000 == 100%
-    uint16  constant public MAX_FEE = 1000; // 10%
-    uint16  constant public ALLOWABLE_EXCHANGE_PERCENTAGE = 9500; // 95%
+    uint16 constant public PERCENTAGE_DENOMINATOR = 10000; // 9800 == 98%, 10000 == 100%
+    uint16 constant public MAX_FEE = 1000; // 10%
+    uint16 constant public ALLOWABLE_EXCHANGE_PERCENTAGE = 9500; // 95%
 
     /// @dev Pays the feeRecipient feeProportion of the total takerEthAmount, denominated in ETH
     /// @param takerEthAmount The total amount that was transacted in WETH, fees are calculated from this value.
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinMarketBuyTokens.sol b/packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol
index 165fec61f..fcc82b705 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinMarketBuyTokens.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol
@@ -20,26 +20,104 @@ pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../utils/LibBytes/LibBytes.sol";
-import "./MixinWethFees.sol";
+import "./MixinFees.sol";
 import "./MixinMarketBuyZrx.sol";
 import "./MixinExpectedResults.sol";
-import "./MixinERC20.sol";
-import "./MixinERC721.sol";
+import "./MixinTransfer.sol";
 import "./MixinConstants.sol";
 import "../protocol/Exchange/libs/LibOrder.sol";
 
 
-contract MixinMarketBuyTokens is
+contract MixinForwarderCore is
     MixinConstants,
-    MixinWethFees,
-    MixinMarketBuyZrx,
     MixinExpectedResults,
-    MixinERC20,
-    MixinERC721
+    MixinFees,
+    MixinMarketBuyZrx,
+    MixinTransfer
 {
     bytes4 public constant ERC20_DATA_ID = bytes4(keccak256("ERC20Token(address)"));
     bytes4 public constant ERC721_DATA_ID = bytes4(keccak256("ERC721Token(address,uint256,bytes)"));
 
+    /// @dev Market sells ETH for ERC20 tokens, performing fee abstraction if required. This does not support ERC721 tokens. This function is payable
+    ///      and will convert all incoming ETH into WETH and perform the trade on behalf of the caller.
+    ///      This function allows for a deduction of a proportion of incoming ETH sent to the feeRecipient.
+    ///      The caller is sent all tokens from the operation.
+    ///      If the purchased token amount does not meet an acceptable threshold then this function reverts.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param feeOrders An array of Order struct containing order specifications for fees.
+    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
+    /// @param feeProportion A proportion deducted off the incoming ETH and sent to feeRecipient. The maximum value for this
+    ///        is 1000, aka 10%. Supports up to 2 decimal places. I.e 0.59% is 59.
+    /// @param feeRecipient An address of the fee recipient whom receives feeProportion of ETH.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForERC20(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint16  feeProportion,
+        address feeRecipient
+    )
+        public
+        payable
+        returns (FillResults memory totalFillResults)
+    {
+        uint256 takerEthAmount = msg.value;
+        require(
+            takerEthAmount > 0,
+            "VALUE_GREATER_THAN_ZERO"
+        );
+        // Deduct the fee from the total amount of ETH sent in
+        uint256 ethFeeAmount = payEthFee(
+            takerEthAmount,
+            feeProportion,
+            feeRecipient
+        );
+        uint256 wethSellAmount = safeSub(takerEthAmount, ethFeeAmount);
+
+        // Deposit the remaining to be used for trading
+        ETHER_TOKEN.deposit.value(wethSellAmount)();
+        // Populate the known assetData, as it is always WETH the caller can provide null bytes to save gas
+        // marketSellOrders fills the remaining
+        address makerTokenAddress = LibBytes.readAddress(orders[0].makerAssetData, 16);
+        orders[0].takerAssetData = WETH_ASSET_DATA;
+        if (makerTokenAddress == address(ZRX_TOKEN)) {
+            // If this is ZRX then we market sell from the orders, rather than a 2 step of buying ZRX fees from feeOrders
+            // then buying ZRX from orders
+            totalFillResults = marketSellEthForZRXInternal(
+                orders,
+                signatures,
+                wethSellAmount
+            );
+        } else {
+            totalFillResults = marketSellEthForERC20Internal(
+                orders,
+                signatures,
+                feeOrders,
+                feeSignatures,
+                wethSellAmount
+            );
+        }
+        // Prevent accidental WETH owned by this contract and it being spent
+        require(
+            takerEthAmount >= totalFillResults.takerAssetFilledAmount,
+            "INVALID_MSG_VALUE"
+        );
+        // Ensure no WETH is left in this contract
+        require(
+            wethSellAmount == totalFillResults.takerAssetFilledAmount,
+            "UNACCEPTABLE_THRESHOLD"
+        );
+        // Transfer all tokens to msg.sender
+        transferERC20Token(
+            makerTokenAddress,
+            msg.sender,
+            totalFillResults.makerAssetFilledAmount
+        );
+        return totalFillResults;
+    }
+
     /// @dev Buys the exact amount of assets (ERC20 and ERC721), performing fee abstraction if required.
     ///      All order assets must be of the same type. Deducts a proportional fee to fee recipient.
     ///      This function is payable and will convert all incoming ETH into WETH and perform the trade on behalf of the caller.
@@ -113,6 +191,85 @@ contract MixinMarketBuyTokens is
         return totalFillResults;
     }
 
+    /// @dev Market sells WETH for ERC20 tokens.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param feeOrders An array of Order struct containing order specifications for fees.
+    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
+    /// @param wethSellAmount The amount of WETH to sell.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForERC20Internal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint256 wethSellAmount
+    )
+        internal
+        returns (FillResults memory totalFillResults)
+    {
+        uint256 remainingWethSellAmount = wethSellAmount;
+        FillResults memory calculatedMarketSellResults = calculateMarketSellResults(orders, wethSellAmount);
+        if (calculatedMarketSellResults.takerFeePaid > 0) {
+            // Fees are required for these orders. Buy enough ZRX to cover the future market buy
+            FillResults memory feeTokensResults = marketBuyZrxInternal(
+                feeOrders,
+                feeSignatures,
+                calculatedMarketSellResults.takerFeePaid
+            );
+            // Ensure the token abstraction was fair if fees were proportionally too high, we fail
+            require(
+                isAcceptableThreshold(
+                    wethSellAmount,
+                    safeSub(wethSellAmount, feeTokensResults.takerAssetFilledAmount)
+                ),
+                "UNACCEPTABLE_THRESHOLD"
+            );
+            remainingWethSellAmount = safeSub(remainingWethSellAmount, feeTokensResults.takerAssetFilledAmount);
+            totalFillResults.takerFeePaid = feeTokensResults.takerFeePaid;
+            totalFillResults.takerAssetFilledAmount = feeTokensResults.takerAssetFilledAmount;
+        }
+        // Make our market sell to buy the requested tokens with the remaining balance
+        FillResults memory requestedTokensResults = EXCHANGE.marketSellOrders(
+            orders,
+            remainingWethSellAmount,
+            signatures
+        );
+        // Update our return FillResult with the market sell
+        addFillResults(totalFillResults, requestedTokensResults);
+        return totalFillResults;
+    }
+
+    /// @dev Market sells WETH for ZRX tokens.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param wethSellAmount The amount of WETH to sell.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForZRXInternal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        uint256 wethSellAmount
+    )
+        internal
+        returns (FillResults memory totalFillResults)
+    {
+        // Make our market sell to buy the requested tokens with the remaining balance
+        totalFillResults = EXCHANGE.marketSellOrders(
+            orders,
+            wethSellAmount,
+            signatures
+        );
+        // Exchange does not special case ZRX in the makerAssetFilledAmount, if fees were deducted then using this amount
+        // for future transfers is invalid.
+        uint256 zrxAmountBought = safeSub(totalFillResults.makerAssetFilledAmount, totalFillResults.takerFeePaid);
+        require(
+            isAcceptableThreshold(totalFillResults.makerAssetFilledAmount, zrxAmountBought),
+            "UNACCEPTABLE_THRESHOLD"
+        );
+        totalFillResults.makerAssetFilledAmount = zrxAmountBought;
+        return totalFillResults;
+    }
+
     /// @dev Buys an exact amount of an ERC20 token using WETH.
     /// @param orders Orders to fill. The maker asset is the ERC20 token to buy. The taker asset is WETH.
     /// @param signatures Proof that the orders were created by their respective makers.
@@ -189,7 +346,7 @@ contract MixinMarketBuyTokens is
             );
         }
         // Transfer all purchased tokens to msg.sender
-        transferToken(
+        transferERC20Token(
             makerTokenAddress,
             msg.sender,
             marketBuyResults.makerAssetFilledAmount
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinMarketSellTokens.sol b/packages/contracts/src/2.0.0/forwarder/MixinMarketSellTokens.sol
deleted file mode 100644
index f4f509846..000000000
--- a/packages/contracts/src/2.0.0/forwarder/MixinMarketSellTokens.sol
+++ /dev/null
@@ -1,197 +0,0 @@
-/*
-
-  Copyright 2018 ZeroEx Intl.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-*/
-
-pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
-
-import "../protocol/Exchange/libs/LibOrder.sol";
-import "../utils/LibBytes/LibBytes.sol";
-import "./MixinWethFees.sol";
-import "./MixinExpectedResults.sol";
-import "./MixinERC20.sol";
-import "./MixinConstants.sol";
-import "./MixinMarketBuyZrx.sol";
-
-
-contract MixinMarketSellTokens is
-    MixinConstants,
-    MixinWethFees,
-    MixinMarketBuyZrx,
-    MixinExpectedResults,
-    MixinERC20
-{
-    /// @dev Market sells ETH for ERC20 tokens, performing fee abstraction if required. This does not support ERC721 tokens. This function is payable
-    ///      and will convert all incoming ETH into WETH and perform the trade on behalf of the caller.
-    ///      This function allows for a deduction of a proportion of incoming ETH sent to the feeRecipient.
-    ///      The caller is sent all tokens from the operation.
-    ///      If the purchased token amount does not meet an acceptable threshold then this function reverts.
-    /// @param orders An array of Order struct containing order specifications.
-    /// @param signatures An array of Proof that order has been created by maker.
-    /// @param feeOrders An array of Order struct containing order specifications for fees.
-    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
-    /// @param feeProportion A proportion deducted off the incoming ETH and sent to feeRecipient. The maximum value for this
-    ///        is 1000, aka 10%. Supports up to 2 decimal places. I.e 0.59% is 59.
-    /// @param feeRecipient An address of the fee recipient whom receives feeProportion of ETH.
-    /// @return FillResults amounts filled and fees paid by maker and taker.
-    function marketSellEthForERC20(
-        LibOrder.Order[] memory orders,
-        bytes[] memory signatures,
-        LibOrder.Order[] memory feeOrders,
-        bytes[] memory feeSignatures,
-        uint16  feeProportion,
-        address feeRecipient
-    )
-        public
-        payable
-        returns (FillResults memory totalFillResults)
-    {
-        uint256 takerEthAmount = msg.value;
-        require(
-            takerEthAmount > 0,
-            "VALUE_GREATER_THAN_ZERO"
-        );
-        // Deduct the fee from the total amount of ETH sent in
-        uint256 ethFeeAmount = payEthFee(
-            takerEthAmount,
-            feeProportion,
-            feeRecipient
-        );
-        uint256 wethSellAmount = safeSub(takerEthAmount, ethFeeAmount);
-
-        // Deposit the remaining to be used for trading
-        ETHER_TOKEN.deposit.value(wethSellAmount)();
-        // Populate the known assetData, as it is always WETH the caller can provide null bytes to save gas
-        // marketSellOrders fills the remaining
-        address makerTokenAddress = LibBytes.readAddress(orders[0].makerAssetData, 16);
-        orders[0].takerAssetData = WETH_ASSET_DATA;
-        if (makerTokenAddress == address(ZRX_TOKEN)) {
-            // If this is ZRX then we market sell from the orders, rather than a 2 step of buying ZRX fees from feeOrders
-            // then buying ZRX from orders
-            totalFillResults = marketSellEthForZRXInternal(
-                orders,
-                signatures,
-                wethSellAmount
-            );
-        } else {
-            totalFillResults = marketSellEthForERC20Internal(
-                orders,
-                signatures,
-                feeOrders,
-                feeSignatures,
-                wethSellAmount
-            );
-        }
-        // Prevent accidental WETH owned by this contract and it being spent
-        require(
-            takerEthAmount >= totalFillResults.takerAssetFilledAmount,
-            "INVALID_MSG_VALUE"
-        );
-        // Ensure no WETH is left in this contract
-        require(
-            wethSellAmount == totalFillResults.takerAssetFilledAmount,
-            "UNACCEPTABLE_THRESHOLD"
-        );
-        // Transfer all tokens to msg.sender
-        transferToken(
-            makerTokenAddress,
-            msg.sender,
-            totalFillResults.makerAssetFilledAmount
-        );
-        return totalFillResults;
-    }
-
-    /// @dev Market sells WETH for ERC20 tokens.
-    /// @param orders An array of Order struct containing order specifications.
-    /// @param signatures An array of Proof that order has been created by maker.
-    /// @param feeOrders An array of Order struct containing order specifications for fees.
-    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
-    /// @param wethSellAmount The amount of WETH to sell.
-    /// @return FillResults amounts filled and fees paid by maker and taker.
-    function marketSellEthForERC20Internal(
-        LibOrder.Order[] memory orders,
-        bytes[] memory signatures,
-        LibOrder.Order[] memory feeOrders,
-        bytes[] memory feeSignatures,
-        uint256 wethSellAmount
-    )
-        internal
-        returns (FillResults memory totalFillResults)
-    {
-        uint256 remainingWethSellAmount = wethSellAmount;
-        FillResults memory calculatedMarketSellResults = calculateMarketSellResults(orders, wethSellAmount);
-        if (calculatedMarketSellResults.takerFeePaid > 0) {
-            // Fees are required for these orders. Buy enough ZRX to cover the future market buy
-            FillResults memory feeTokensResults = marketBuyZrxInternal(
-                feeOrders,
-                feeSignatures,
-                calculatedMarketSellResults.takerFeePaid
-            );
-            // Ensure the token abstraction was fair if fees were proportionally too high, we fail
-            require(
-                isAcceptableThreshold(
-                    wethSellAmount,
-                    safeSub(wethSellAmount, feeTokensResults.takerAssetFilledAmount)
-                ),
-                "UNACCEPTABLE_THRESHOLD"
-            );
-            remainingWethSellAmount = safeSub(remainingWethSellAmount, feeTokensResults.takerAssetFilledAmount);
-            totalFillResults.takerFeePaid = feeTokensResults.takerFeePaid;
-            totalFillResults.takerAssetFilledAmount = feeTokensResults.takerAssetFilledAmount;
-        }
-        // Make our market sell to buy the requested tokens with the remaining balance
-        FillResults memory requestedTokensResults = EXCHANGE.marketSellOrders(
-            orders,
-            remainingWethSellAmount,
-            signatures
-        );
-        // Update our return FillResult with the market sell
-        addFillResults(totalFillResults, requestedTokensResults);
-        return totalFillResults;
-    }
-
-    /// @dev Market sells WETH for ZRX tokens.
-    /// @param orders An array of Order struct containing order specifications.
-    /// @param signatures An array of Proof that order has been created by maker.
-    /// @param wethSellAmount The amount of WETH to sell.
-    /// @return FillResults amounts filled and fees paid by maker and taker.
-    function marketSellEthForZRXInternal(
-        LibOrder.Order[] memory orders,
-        bytes[] memory signatures,
-        uint256 wethSellAmount
-    )
-        internal
-        returns (FillResults memory totalFillResults)
-    {
-        // Make our market sell to buy the requested tokens with the remaining balance
-        totalFillResults = EXCHANGE.marketSellOrders(
-            orders,
-            wethSellAmount,
-            signatures
-        );
-        // Exchange does not special case ZRX in the makerAssetFilledAmount, if fees were deducted then using this amount
-        // for future transfers is invalid.
-        uint256 zrxAmountBought = safeSub(totalFillResults.makerAssetFilledAmount, totalFillResults.takerFeePaid);
-        require(
-            isAcceptableThreshold(totalFillResults.makerAssetFilledAmount, zrxAmountBought),
-            "UNACCEPTABLE_THRESHOLD"
-        );
-        totalFillResults.makerAssetFilledAmount = zrxAmountBought;
-        return totalFillResults;
-    }
-
-}
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol b/packages/contracts/src/2.0.0/forwarder/MixinTransfer.sol
index 23c130d69..78a542892 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinTransfer.sol
@@ -17,13 +17,37 @@
 */
 
 pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
 
+import "../utils/LibBytes/LibBytes.sol";
+import "../tokens/ERC721Token/IERC721Token.sol";
 
-contract MixinERC20 {
+
+contract MixinTransfer {
+
+    using LibBytes for bytes;
 
     bytes4 constant internal ERC20_TRANSFER_SELECTOR = bytes4(keccak256("transfer(address,uint256)"));
+    bytes4 constant internal ERC721_RECEIVED = bytes4(keccak256("onERC721Received(address,uint256,bytes)"));
+    bytes4 constant internal ERC721_RECEIVED_OPERATOR = bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"));
+
+    function onERC721Received(address, uint256, bytes memory)
+        public
+        pure
+        returns(bytes4)
+    {
+        return ERC721_RECEIVED;
+    }
+
+    function onERC721Received(address, address, uint256, bytes memory)
+        public
+        pure
+        returns(bytes4)
+    {
+        return ERC721_RECEIVED_OPERATOR;
+    }
 
-    function transferToken(
+    function transferERC20Token(
         address token,
         address to,
         uint256 amount
@@ -64,4 +88,22 @@ contract MixinERC20 {
             "TRANSFER_FAILED"
         );
     }
+
+    function transferERC721Token(
+        bytes memory assetData,
+        address to
+    )
+        internal
+    {
+        // Decode asset data.
+        address token = assetData.readAddress(16);
+        uint256 tokenId = assetData.readUint256(36);
+        bytes memory receiverData = assetData.readBytesWithLength(100);
+        IERC721Token(token).safeTransferFrom(
+            address(this),
+            to,
+            tokenId,
+            receiverData
+        );
+    }
 }