function init(ERC20 _baseToken, ERC20 _rwrdToken) public {
    require(msg.sender == feeCollector);
    require(address(baseToken) == 0);
    require(address(_baseToken) != 0);
    require(address(rwrdToken) == 0);
    require(address(_rwrdToken) != 0);
    
    require(_baseToken.totalSupply() > 0);
    baseToken = _baseToken;
    require(_rwrdToken.totalSupply() > 0);
    rwrdToken = _rwrdToken;
  }