event.js

{
    "_id" : "123",
    "name" : "Weekend Game",
    "interval" : {
        "from" : ISODate("2017-05-22T10:00:00.000Z"),
        "to" : ISODate("2017-05-22T12:00:00.000Z")
    },
    "requiredParticipants" : 12,
    "participants" : [ 
        {
            "_id" : "123"
        }, 
        {
            "_id" : "234"
        }
    ],
    "place" : {
        "_id" : "123",
        "address" : {
            "formatted" : "Minsk, Pushkina st. 14"
        }
    }
}