reduce number of test for large set contentions.
reduce number of test for large set contentions.

jongwook/incubator-s2graph,SteamShon/incubator-s2graph,daewon/incubator-s2graph,SteamShon/incubator-s2graph,SteamShon/incubator-s2graph,jongwook/incubator-s2graph,daewon/incubator-s2graph