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ballot.sol

pragma solidity ^0.5.12;
contract PhotoContestContract {
    bytes32 _name;
    address _owner;
    bytes32[] _ipfsPhotoHashes;
    address payable[] _submissionAddresses;
    
    constructor(bytes32 name) public {
        _owner = msg.sender;
        _name = name;
    }
    function submit(bytes32 photoHash) public {
        _submissionAddresses.push(msg.sender);
        _ipfsPhotoHashes.push(photoHash);
    } 
    function getSubmissions() public view returns (bytes32[] memory) {   
        return _ipfsPhotoHashes; 
    }
    function selectWinner(bytes32 photoHash) public {
        require(msg.sender == _owner, "You are not the owner.");    
        
        for (uint n = 0; n < _ipfsPhotoHashes.length; n++) {
            if (_ipfsPhotoHashes[n] == photoHash) {
                address payable winner = _submissionAddresses[n];
                // send eth to winner address
                winner.transfer(address(this).balance);
            }
        }
    } 
}

ballot_test.sol

pragma solidity >=0.4.22 <0.6.0;
import "remix_tests.sol"; // this import is automatically injected by Remix.
import "./ballot.sol";

contract test3 {
   
    Ballot ballotToTest;
    function beforeAll () public {
       ballotToTest = new Ballot(2);
    }
    
    function checkWinningProposal () public {
        ballotToTest.vote(1);
        Assert.equal(ballotToTest.winningProposal(), uint(1), "1 should be the winning proposal");
    }
    
    function checkWinninProposalWithReturnValue () public view returns (bool) {
        return ballotToTest.winningProposal() == 1;
    }
}