function challengeReparameterization(bytes32 _propID) public returns (uint challengeID) {
        ParamProposal memory prop = proposals[_propID];
        uint deposit = prop.deposit;

        require(propExists(_propID) && prop.challengeID == 0);

        
        uint pollID = voting.startPoll(
            get("pVoteQuorum"),
            get("pCommitStageLen"),
            get("pRevealStageLen")
        );

        challenges[pollID] = Challenge({
            challenger: msg.sender,
            rewardPool: SafeMath.sub(100, get("pDispensationPct")).mul(deposit).div(100),
            stake: deposit,
            resolved: false,
            winningTokens: 0
        });

        proposals[_propID].challengeID = pollID;       

        
        require(token.transferFrom(msg.sender, this, deposit));

        (uint commitEndDate, uint revealEndDate,,,) = voting.pollMap(pollID);

        emit _NewChallenge(_propID, pollID, commitEndDate, revealEndDate, msg.sender);
        return pollID;
    }