hmarr/mongoengine — comment on commit 7b1860d17b0d60bd11aaace9052bd58a2d702cbf
File:  line 0
By linuxnow:

IMHO it should be a set instead of a list; if we want a list it should be a heapq to keep it almost sorted.
But a set seems a better implementation as we don't expect too many nodes in there.