TEST(LtOp, MatchesMaxKey) {
    BSONObj operand = BSON("a" << MaxKey);
    LTMatchExpression lt;
    ASSERT(lt.init("a", operand["a"]).isOK());
    ASSERT(!lt.matchesBSON(BSON("a" << MaxKey), NULL));
    ASSERT(lt.matchesBSON(BSON("a" << MinKey), NULL));
    ASSERT(lt.matchesBSON(BSON("a" << 4), NULL));
}
TEST(LtOp, MatchesMaxKey) {
    BSONObj operand = BSON("a" << MaxKey);
    LTMatchExpression lt;
    ASSERT(lt.init("a", operand["a"]).isOK());
    ASSERT(!lt.matchesBSON(BSON("a" << MaxKey), NULL));
    ASSERT(lt.matchesBSON(BSON("a" << MinKey), NULL));
    ASSERT(lt.matchesBSON(BSON("a" << 4), NULL));
}