Checks that locations are correctly resolved for gutter click.

3: breakpointAdded(3, 11)
4: breakpointAdded(4, 8)
5: breakpointAdded(5, 0)
6: breakpointAdded(6, 0)
11: breakpointAdded(11, 0)
12: breakpointAdded(12, 0)
13: breakpointAdded(13, 0)