+sinter(Client, Keys) -> sintersect(Client, Keys).
+sinterstore(Client, DstKey, Keys) -> client:ssend(Client, sinterstore, [DstKey|Keys]).
+sunion(Client, Keys) -> client:ssend(Client, sunion, Keys).
+sunionstore(Client, DstKey, Keys) -> client:ssend(Client, sunionstore, [DstKey|Keys]).
+sdiff(Client, Keys) -> client:ssend(Client, sdiff, Keys).
+sdiffstore(Client, DstKey, Keys) -> client:ssend(Client, sdiffstore, [DstKey|Keys]).