Duplicate Key Entry in Cache Collection

[rafaelgom3s]

I'm experiencing duplicated cache entries when using the MongoDB engine with cacheman.

Below is the partial output of the collection used by cacheman to persist the cache. Has you may notice the key cacheman:flows:User:77FhwgJtDQyPTSs9u is present twice.

/* 1 */
{
    "_id" : ObjectId("59cd076bd24488ac2138fc4a"),
    "key" : "cacheman:flows:User:77FhwgJtDQyPTSs9u",
    "value" : "{\"checkin\":{\"context\":{\"dates\":{\"date_start\":1506637800,\"date_end\":1506643199},\"state\":\"request\",\"type\":\"invalid_project\",\"flowData\":{\"records\":[{\"hours\":8}]}},\"active\":true,\"finished\":false}}",
    "expireAt" : ISODate("2017-10-28T14:30:03.441Z")
}

/* 2 */
{
    "_id" : ObjectId("59cd076bd24488ac2138fc49"),
    "key" : "cacheman:flows:User:77FhwgJtDQyPTSs9u",
    "value" : "{\"checkin\":{\"context\":{\"dates\":{\"date_start\":1506637800,\"date_end\":1506643199},\"state\":\"request\",\"type\":\"invalid_project\",\"flowData\":{\"records\":[{\"hours\":8}]}},\"active\":true,\"finished\":false}}",
    "expireAt" : ISODate("2017-10-28T14:30:03.436Z")
}

Is this a bug or a feature? 😄