    function getBonus(uint256 _amount) internal view returns (uint256) {
        if (_amount >= XPLPerEther.mul(5)) {
            return ((20 * _amount).div(100)).add(_amount);  
        } else if (_amount >= XPLPerEther) {
            return ((5 * _amount).div(100)).add(_amount);  
        }
        return _amount;
    }