Tooptip positioning

[ckrobinson83]

Hi. I tried to email someone about this, but apparently the email doesn't work, so I thought I'd try here.
I'm making a line chart, and I'd like to make it so the tooltip bubble stays with the line from data point to data point rather than following the mouse (See link since there doesn't seem to be a way to post pictures).

The docs reference a way to manually position where the tool tip is, but I didn't see any information on how to actually do that.

Something along the lines of what happens in the chart at this link is what I need:
https://bl.ocks.org/Qizly/5a78caaf03ed96757e72

I'd post the images, but it seems like there's no way to do that here.

Thanks for any help.