constructor() public {
        oraclize_setProof(proofType_TLSNotary | proofStorage_IPFS);
        
        oraclize_setCustomGasPrice(30000000000 wei);
        horses.BTC = bytes32("BTC");
        horses.ETH = bytes32("ETH");
        horses.LTC = bytes32("LTC");
        owner = msg.sender;
        horses.customPreGasLimit = 100000;
        horses.customPostGasLimit = 200000;
    }