Previously we sorted a list e.g. [3,2,1]
that we already got, then fetched another
list e.g. [6,7,8,2]. Instead of just
sorting the new list and manually merging it
we would sort the appended lists:
[1,2,3, 6,7,8,2]
Despite mergesort, this is now optimized in
a two-step process:
* ONLY sort the new list
* call a Merge function on both lists, that assumes
sorted and deduplicated lists
This should be faster.