/// @notice Migrates an ERC-721 token to the new vault after a successful migration
/// @param _vault Address of the vault
/// @param _proposalId ID of the proposal
/// @param _token Address of the ERC-721 token
/// @param _tokenId ID of the token
/// @param _erc721TransferProof Merkle proof for transferring an ERC-721 token
function migrateVaultERC721(
    address _vault,
    uint256 _proposalId,
    address _token,
    uint256 _tokenId,
    bytes32[] calldata _erc721TransferProof
) external {
    address newVault = migrationInfo[_vault][_proposalId].newVault;
    // Withdraws an ERC-721 token from the old vault and transfers to the new vault
    IBuyout(buyout).withdrawERC721(
        _vault,
        _token,
        newVault,
        _tokenId,
        _erc721TransferProof
    );
}
function IBuyout(buyout).withdrawERC721(
    address _vault,
    address _token,
    address _to,
    uint256 _tokenId,
    bytes32[] calldata _erc721TransferProof
) external {
    // Reverts if address is not a registered vault
    (, uint256 id) = IVaultRegistry(registry).vaultToToken(_vault);
    if (id == 0) revert NotVault(_vault);
    // Reverts if auction state is not successful
    (, address proposer, State current, , , ) = this.buyoutInfo(_vault);
    State required = State.SUCCESS;
    if (current != required) revert InvalidState(required, current);
    // Reverts if caller is not the auction winner
    if (msg.sender != proposer) revert NotWinner();

    // Initializes vault transaction
    bytes memory data = abi.encodeCall(
        ITransfer.ERC721TransferFrom,
        (_token, _vault, _to, _tokenId)
    );
    // Executes transfer of ERC721 token to caller
    ..SNIP..
}
function migrateVaultERC721(
    address _vault,
    uint256 _proposalId,
    address _token,
    uint256 _tokenId,
    bytes32[] calldata _erc721TransferProof
) external {
    address newVault = migrationInfo[_vault][_proposalId].newVault;
+    if (newVault == address(0)) reverts VaultDoesNotExistOrInvalid;
    
    // Withdraws an ERC-721 token from the old vault and transfers to the new vault
    IBuyout(buyout).withdrawERC721(
        _vault,
        _token,
        newVault,
        _tokenId,
        _erc721TransferProof
    );
}
function withdrawERC721(
    address _vault,
    address _token,
    address _to,
    uint256 _tokenId,
    bytes32[] calldata _erc721TransferProof
) external {
    // Reverts if address is not a registered vault
    (, uint256 id) = IVaultRegistry(registry).vaultToToken(_vault);
    if (id == 0) revert NotVault(_vault);
+   if (_to == 0) revert ToAddressIsZero(); 
    // Reverts if auction state is not successful
    (, address proposer, State current, , , ) = this.buyoutInfo(_vault);
    State required = State.SUCCESS;
    if (current != required) revert InvalidState(required, current);
    // Reverts if caller is not the auction winner
    if (msg.sender != proposer) revert NotWinner();

    // Initializes vault transaction
    bytes memory data = abi.encodeCall(
        ITransfer.ERC721TransferFrom,
        (_token, _vault, _to, _tokenId)
    );
    // Executes transfer of ERC721 token to caller
    IVault(payable(_vault)).execute(transfer, data, _erc721TransferProof);
}
