function mint() external payable {
    (uint err,) = mintInternal(msg.value);
    requireNoError(err, "mint failed");
}
function mint(uint256 mintAmount) external payable virtual returns (uint256);
CToken ctoken = cTokenRegistry.fetchCToken(underlying);
uint256 initialTokens = ctoken.balanceOf(address(this));

address addr = account.addr();

if (repayDebt) {
    amount -= _repayAnyDebt(addr, underlying, amount, ctoken);
    if (amount == 0) return true;
}

uint256 err;
if (underlying == address(0)) {
    err = ctoken.mint{value: amount}(amount);
}
