Does Material Design have a guideline for styling a "select all" checkbox?

I have a list of checkboxes and would like to add a "select-all" toggle. I already have it working, including setting an indeterminate state when some of the items are selected. What I'd like to know is, when the list is a capital-L List, does Material specify how to place the select-all box?

I currently have it inline with the rest of the list, but I don't like the way it looks:

I'm thinking of putting it as a secondary action (on the right side) of the section header but that could introduce its own issues. I'm hoping there's a "right" way to do this but I'll settle for suggestions if not.