EitanRs3a:PRIMARY> db.sbtest1.findOne()
{
        "_id" : NumberLong(32545793),
        "payload" : "o????h?.%nE\u000eS\\_\u0011rj\u001a??5M??/d??q\u0014;?????z
5X??^??\fWd???#?\u001cEz\u001c`??!J\u001d?L$F?\u001a????(lc??P?o#?|;\b\f?_????^{
?sS?6?{,\u0007<\u0017???I\u001b?=?2?&G\u000eM?vZ?F\u0011\u000f0????Y?^????~??c\u
001d^???s?F\u0007?!\r?D$\u0001?\u000bx4\u0011?f0\u0002?N(??\\\u0006Uu\u001fo\u00
01l?iQi\u000eG'z?9?;i?\u0017u\u0000L?L?G??\u0003?W?ja\u0011\ft\u000e??\u00185??S
??\n???-\u0003??????\u000f\u0012??R?c?A\u001b\u001e?<\u0017\u0014?$\u0004C,\"?\u
001e?\b6T\b?uq?V??'\u0000'-¦U\u0012A?\u0019\u0005?\u001d\u0014elVh?=6??%W\u0019\
u0005(¦m??????J$k;HC0?-l\\J?c??.AJ?\u0016qbq,?q?\u001fr??LO?'\u000e\u0012E?\u000
2A\u0000\u0019\u000ei%?P74?\"???b\\s(???P7??L???\u0019N\r??k?&?9?w~20??W\u0002?4
t??\u0006tz??&o'O]??8??Moq\u001a??\u0006?*\u0013?\u0005c-?b?\u000et?=W?S?%&?(F??
)\u001033?x$??,??\u0016??\b?qhb?\u0006?\t?a?/r\u0016?a?R\u000fL?Z?'?e?6?/\u00160
\u0012?c\u001bk?\u001c@y?|?JzV?3?<\r?K??X???=aQ*o?v5?X??F\u001a????L\f?????Y\u00
1f\u001f??76??\u0001fA????\u001d?q???32\u001e?????{k?o?a?\u0015G%??\u000b^4?kH?U
\u0012\u0014?e?-??\u0000?n\b5?????\u0012n?~1???\u0012?~_?\u0007\t?b??8????\u0001
?WYh?f?9\u0003?k\b?\n`]d?5????j??\u0013??l?^??z???Y^_??????b?\u0010Z??n\u001ai \
u0013???(\u0013w?+$??YLA\\\u0011\u0019\u001a?)!\u001c?????\u000e?*?\u0004uN??HwD
???t%@???c??/,?\u000f?9I\u0003?3*:~?\b? @:\u0000O\u0013[\n!+}FR8\u0012?ZTD?b%??a
\u0003?z??N;?F??`^???\n??q\u0019}??\u0004a\u0018\u0011?IO?H???k\u0016z?<????\\-?
-?v\u0016?\u0011???e?!\f)\u0005h???'?;L\u0001&\u000f^\n?qY>??I1=w\u0014?\u000fN?
oe|?\\y?/I}[???/???+??\t<e??\u000fkPr??\u0013?\u0017~??L?\t?g\f\u000f\u000e?9??d
\u0003?=r???e+?@\u000e\u000e??\u0010l8\u0017?X??S?5\u001f???]??o?\\?)??[P??,¦u¦d
F?4?\u000f<1.\u0015G?-I?=????@",
        "group" : NumberLong("4862608266472634149"),
        "createdAt" : ISODate("2015-07-08T15:13:45.211Z")
}

EitanRs3a:PRIMARY> db.sbtest1.getIndexes()
[
        {
                "v" : 1,
                "key" : {
                        "_id" : 1
                },
                "name" : "_id_",
                "ns" : "sbtest1.sbtest1"
        },
        {
                "v" : 1,
                "key" : {
                        "createdAt" : 1
                },
                "name" : "createdAt_1",
                "ns" : "sbtest1.sbtest1",
                "expireAfterSeconds" : 20
        }
]