Code review comment for lp://qastaging/~thisfred/desktopcouch/list-to-mergeable-list-mapping

+1.

Tests pass, in spite of our best efforts with the debugger to break them. An apparent off-by-one error turned out not to be. Could we have a more comprehensive docstring to explain that the UUID associated with a given element may change if the order of the element values changes, even if the new element values are the same as the current ones apart from the order?