How does checkForUpdates work?

The electron auto-update documentation recommends using this to poll for updates:

setInterval(() => {
  autoUpdater.checkForUpdates()
}, 60000)

Let’s say I call checkForUpdates() and it finds and downloads an update (update-downloaded fires.

What happens if checkForUpdates() gets called in the next minute? Will it re-download the file? Or will it recognize that it already has the current download I am trying to check for updates every hour, but automatically update at specific times of day and want to make sure I’m not re-downloading the same file every hour.

I’ve looked at the source code, but I think the part I’m looking for is buried in the Squirrel.Mac source code.