Collapsing on <latitude> then <longitude> doesn't always give the same results as collapsing on <longitude> and <latitude>, as the second coordinate is dependent on the results of the first. The <test_peak_2d> looks at collapsing the coordinates one way, then the other, but the example I picked does give the same results. Should I create another test that shows they are different, or change <test_peak_2d> so the results aren't the same?