Manually test with the following steps:

1. Scroll with momentum to the green box in the first div.

2. In the first div, drag so the blue box is partially visible, then let go so the div snaps back to show green.

3. Scroll with momentum to the green box in the second div.

4. In the second div, drag so the blue box is partially visible, then let go so the div snaps back to show green.

* Swiping with momentum in topTarget with scroll offset 0
topTarget now has scroll offset 400
bottomTarget now has scroll offset 0

* Swiping without momentum in topTarget with scroll offset 400
topTarget now has scroll offset 400
bottomTarget now has scroll offset 0

* Swiping with momentum in bottomTarget with scroll offset 0
topTarget now has scroll offset 400
bottomTarget now has scroll offset 400

* Swiping without momentum in bottomTarget with scroll offset 400
topTarget now has scroll offset 400
bottomTarget now has scroll offset 400