    function transferFrom(
        address _from,
        address _to,
        uint256 _value
    ) public override returns (bool) {
        require(_allowances[_from][msg.sender] >= _value, "Allowance too low");
        uint256 creditAmount = creditsForTokenBalance(_value);
        creditBalances[_from] = creditBalances[_from] - creditAmount;
        creditBalances[_to] = creditBalances[_to] + creditAmount;
        emit Transfer(_from, _to, _value);
