function is only called by token sales.
    
    
    
    
    function mintTimeLocked (
        address _beneficiary,
        uint256 _tokenAmount,
        uint256 _releaseTime
    ) external onlyTokenSale returns(bool) {
        require(isStarted && !isFinalized);
        require(TokenController(tokenControllerAddr).mint(this, _tokenAmount));
        require(ERC20Interface(token).approve(timeLockPoolAddr, _tokenAmount));
        require(TimeLockPool(timeLockPoolAddr).depositERC20(
            token,
            _beneficiary,
            _tokenAmount,
            _releaseTime
        ));
        return true;
    }