>    * @param amount amount of the ERC-20 token to be wrapped, in terms of
     *  18-decimal fixed point
     * @param userAddress the address of the user who is wrapping the token
     */
>   function _erc20Wrap(address tokenAddress, uint256 amount, address userAddress, uint256 outputToken) private {
        } else if (interactionType == InteractionType.WrapErc20) {
            inputToken = 0;
            inputAmount = 0;
            outputToken = specifiedToken;
>          outputAmount = specifiedAmount;
>           _erc20Wrap(externalContract, outputAmount, userAddress, outputToken);
        if (outputAmount > 0) {
            // since uint, same as (outputAmount != 0)
            _mint(userAddress, outputToken, outputAmount);
        }
