// Contract: TwuToken
// Target function: function append(buffer memory _buf, bytes memory _data) internal pure returns (buffer memory _buffer)
pragma solidity ^0.6.10;
pragma experimental ABIEncoderV2;

// Dummy contract only used to emit to end-user they are using wrong solc
abstract contract solcChecker {
/* INCOMPATIBLE SOLC: import the following instead: "github.com/oraclize/ethereum-api/oraclizeAPI_0.4.sol" */ function f(bytes calldata x) virtual external;
}

interface ProvableI {

    function cbAddress() external returns (address _cbAddress);
    function setProofType(byte _proofType) external;
    function setCustomGasPrice(uint _gasPrice) external;
    function getPrice(string calldata _datasource) external returns (uint _dsprice);
    function randomDS_getSessionPubKeyHash() external view returns (bytes32 _sessionKeyHash);
    function getPrice(string calldata _datasource, uint _gasLimit)  external returns (uint _dsprice);
    function queryN(uint _timestamp, string calldata _datasource, bytes calldata _argN) external payable returns (bytes32 _id);
    function query(uint _timestamp, string calldata _datasource, string calldata _arg) external payable returns (bytes32 _id);
    function query2(uint _timestamp, string calldata _datasource, string calldata _arg1, string calldata _arg2) external payable returns (bytes32 _id);
    function query_withGasLimit(uint _timestamp, string calldata _datasource, string calldata _arg, uint _gasLimit) external payable returns (bytes32 _id);
    function queryN_withGasLimit(uint _timestamp, string calldata _datasource, bytes calldata _argN, uint _gasLimit) external payable returns (bytes32 _id);
    function query2_withGasLimit(uint _timestamp, string calldata _datasource, string calldata _arg1, string calldata _arg2, uint _gasLimit) external payable returns (bytes32 _id);
}

interface OracleAddrResolverI {
    function getAddress() external returns (address _address);
}
/*
Begin solidity-cborutils
https://github.com/smartcontractkit/solidity-cborutils
MIT License
Copyright (c) 2018 SmartContract ChainLink, Ltd.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
library Buffer {

    struct buffer {
        bytes buf;
        uint capacity;
    }

    function init(buffer memory _buf, uint _capacity) internal pure {
        uint capacity = _capacity;
        if (capacity % 32 != 0) {
            capacity += 32 - (capacity % 32);
        }
        _buf.capacity = capacity; // Allocate space for the buffer data
        assembly {
            let ptr := mload(0x40)
            mstore(_buf, ptr)
            mstore(ptr, 0)
            mstore(0x40, add(ptr, capacity))
        }
    }

    function resize(buffer memory _buf, uint _capacity) private pure {
        bytes memory oldbuf = _buf.buf;
        init(_buf, _capacity);
        append(_buf, oldbuf);
    }

    function max(uint _a, uint _b) private pure returns (uint _max) {
        if (_a > _b) {
            return _a;
        }
        return _b;
    }