small refactor of arraySum and don't need arrayIntersect anymore.
small refactor of arraySum and don't need arrayIntersect anymore.


Former-commit-id: d82a6f1e418ec6dbe26935207626c9b7819a07c2 [formerly 503db1c23899a6ebde97477aecd0d903ce2667e2]
Former-commit-id: ef67b1548f8aca670a3364ef12f09e7178057380
romancow/Sugar,romancow/Sugar,andrewplummer/Sugar,andrewplummer/Sugar