db.test.mapReduce(
    function() {
        var map = new Map()
        map.put("A", "B")

        emit(map.get("A"), { count: 1 })
    },
    function(key, records) { 
        counter = { count: 0 }
        
        for (var idx = 0; idx < records.length; idx++) {
            counter.count += records[idx].count
        }
        
        return counter
    },
    { 
      out: { inline: 1 }
    }
)