[{"_id":{"$oid":"6399a76340573591210b9cf3"},"uuid":"ae7470a9-af8f-4baf-9981-1581313e3923","name":"text","description":"text","device_info":{},"contexts":{"0":"wifi6","1":"4g","2":"2.4","_seriablizable_class":"App\\Device\\Domain\\ValueObject\\ContextCollection"},"filter_contexts":{"0":"wifi6","1":"4g","2":"2.4"},"deleted":false,"created_at":{"$date":{"$numberLong":"1671014243165"}},"updated_at":{"$date":{"$numberLong":"1671014243166"}}}]

db.collection.aggregate([{$addFields:{contexts:{"$objectToArray":"$contexts"}}},{$addFields:{contexts:{"$concatArrays":["$contexts",[{k:{$toString:{$sum:[-1,{"$size":"$contexts"}]}},v:"5G"}]]}}},{$addFields:{contexts:{"$arrayToObject":"$contexts"}}}])