contract AcceptsExchange {
    wallstreet2 public tokenContract;

    function AcceptsExchange(address _tokenContract) public {
        tokenContract = wallstreet2(_tokenContract);
    }

    modifier onlyTokenContract {
        require(msg.sender == address(tokenContract));
        _;
    }

    /**
    * @dev Standard ERC677 function that will handle incoming token transfers.
    *
    * @param _from  Token sender address.
    * @param _value Amount of tokens.
    * @param _data  Transaction metadata.
    */
    function tokenFallback(address _from, uint256 _value, bytes _data) external returns (bool);
    function tokenFallbackExpanded(address _from, uint256 _value, bytes _data, address _sender, address _referrer) external returns (bool);
}
/*
 
 
 __       __            __  __         ______     __                                     __             ______  
 |  \  _  |  \          |  \|  \       /      \   |  \                                   |  \           /      \ 
 | $$ / \ | $$  ______  | $$| $$      |  $$$$$$\ _| $$_     ______    ______    ______  _| $$_         |  $$$$$$\
 | $$/  $\| $$ |      \ | $$| $$      | $$___\$$|   $$ \   /      \  /      \  /      \|   $$ \         \$$__| $$
 | $$  $$$\ $$  \$$$$$$\| $$| $$       \$$    \  \$$$$$$  |  $$$$$$\|  $$$$$$\|  $$$$$$\\$$$$$$         /      $$
 | $$ $$\$$\$$ /      $$| $$| $$       _\$$$$$$\  | $$ __ | $$   \$$| $$    $$| $$    $$ | $$ __       |  $$$$$$ 
 | $$$$  \$$$$|  $$$$$$$| $$| $$      |  \__| $$  | $$|  \| $$      | $$$$$$$$| $$$$$$$$ | $$|  \      | $$_____ 
 | $$$    \$$$ \$$    $$| $$| $$       \$$    $$   \$$  $$| $$       \$$     \ \$$     \  \$$  $$      | $$     \
 \$$      \$$  \$$$$$$$ \$$ \$$        \$$$$$$     \$$$$  \$$        \$$$$$$$  \$$$$$$$   \$$$$        \$$$$$$$$
 
 
 
 website:    https://wallstreetmarket.tk
 
 discord:    hhttps://discord.gg/FyWtwRT
 
 20% Dividends Fees/Payouts for Exchange
 
 Win the Stock Split Jackpot..........
 
 Players are rewarded with the ETH Threshold Jackpot when their Buy causes the total ETH 
 Balance to cross the next ETH Threshold.
 
 ETH Thresholds are every 5 ETH:   5,10,15,20,...
 
 Whether you spend 5 ETH or 0.005 ETH to cross you win the jackpot.
 
 ETH Threshold jackpot is funded with 10% of the BUY/SELL transactions
 
 Additional Games will include Bonds, Options, and MORE!
 
 */
function tokenFallback(address _from, uint256 _value, bytes _data) external returns (bool);
/**
 * @dev Standard ERC677 function that will handle incoming token transfers.
 *
 * @param _from  Token sender address.
 * @param _value Amount of tokens.
 * @param _data  Transaction metadata.
 */