Este contrato recolecta ETH a cambio de tokens de votación. ¿Qué función me permitirá transferir el ETH recolectado a una billetera?

pragma solidity ^0.4.23;

contract Voting {
    bytes32[] public candidateList;

    uint public totalTokens;
    uint public balanceTokens;
    uint public tokenPrice;

    // what is the voter address?
    // total tokens purchased
    // tokens voted per candidate 

    struct voter {
        address voterAddress;
        uint tokensBought;
        uint[] tokensUsedPerCandidate;
    }

    mapping(address => voter) public voterInfo;
    mapping(bytes32 => uint) public votesReceived;

    constructor (uint _totalTokens, uint _tokenPrice, bytes32[] _candidateNames) public {
        totalTokens = _totalTokens;
        balanceTokens = _totalTokens;
        tokenPrice = _tokenPrice;
        candidateList = _candidateNames;
    }

    //1. Users should be able to purchase tokens 
    //2. Users should be able to vote for candidates with tokens
    //3. Anyone should have the ability to lookup voter info

    function buy() payable public {
        uint tokensToBuy = msg.value / tokenPrice;
        require(tokensToBuy <= balanceTokens);
        voterInfo[msg.sender].voterAddress = msg.sender;
        voterInfo[msg.sender].tokensBought += tokensToBuy;
        balanceTokens -= tokensToBuy;
    }

    function voteForCandidate(bytes32 candidate, uint tokens) public {
        // Check to make sure user has enough tokens to vote
        // Increment vote count for candidate
        // Update the voter struct tokensUsedPerCandidate for this voter

        uint availableTokens = voterInfo[msg.sender].tokensBought - totalTokensUsed(voterInfo[msg.sender].tokensUsedPerCandidate);

        require(tokens <= availableTokens, "You don't have enough tokens");
        votesReceived[candidate] += tokens;

        if (voterInfo[msg.sender].tokensUsedPerCandidate.length == 0) {
            for(uint i=0; i<candidateList.length; i++) {
                voterInfo[msg.sender].tokensUsedPerCandidate.push(0);
            }
        }

        uint index = indexOfCandidate(candidate);
        voterInfo[msg.sender].tokensUsedPerCandidate[index] += tokens;
    }

    function indexOfCandidate(bytes32 candidate) view public returns(uint) {
        for(uint i=0; i<candidateList.length; i++) {
            if (candidateList[i] == candidate) {
                return i;
            }
        }
        return uint(-1);
    }

    function totalTokensUsed(uint[] _tokensUsedPerCandidate) private pure returns (uint) {
        uint totalUsedTokens = 0;
        for(uint i=0; i<_tokensUsedPerCandidate.length; i++) {
            totalUsedTokens += _tokensUsedPerCandidate[i];
        }
        return totalUsedTokens;
    }

    function voterDetails(address user) view public returns (uint, uint[]) {
        return (voterInfo[user].tokensBought, voterInfo[user].tokensUsedPerCandidate);
    }

    function tokensSold() public view returns (uint) {
        return totalTokens - balanceTokens;
    }

    function allCandidates() public view returns (bytes32[]) {
        return candidateList;
    }

    function totalVotesFor(bytes32 candidate) public view returns (uint) {
        return votesReceived[candidate];
   }
}