Topeak Bike Rack Tail Light Mount Adaptor

I needed an adaptor plate to mount my tail light to the license-plate-region of my Topeak bike rack. This style of tail light seems pretty common, so I hope this helps someone else out.

Update
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After using this for a couple days on the trail, my light did pop out once after a jostling bump. I've temporarily fixed this with a hack -- wrapping a rubber band or hair elastic around it to keep it held down. When I get some more time, I'll be adding a mechanism to help keep it clipped or