Create a Total Match Posting

[Matt McCormick]

Hello,

I'm trying to write my first importer with beancount.

How do I create a Posting that results in a Total Match?

The output should be something like:

Assets:Invest -60 HOOL {}

I've tried setting the `cost` param to None and also creating a `Cost` and `CostSpec` tuple with the numbers set to None but all those seem to avoid printing out the Cost basis and I can't seem to figure out how to output a total match.

Thanks