How insert new array into existing embedded array in C#? - arrays

Question

I have a little bit problem with an data update in mongoDB. I have an array embedded in an other array who is embedded in a document (yaaaaay ^^). So my collection is like that :
{
"_id" : ObjectId("5965e0b4f1042c4c3f1d8edc"),
"Builder" : "Google",
"Family" : "Car",
"ProductName" : "ABCD_80A_PU170017",
"ProductNumber" : "N 1",
"Test" : [
{
"Num_Test" : "PU170017",
"Date_Start" : ISODate("2017-07-12T00:00:00.000Z"),
"Bench": [
{
"Room": 1,
"Num" : 1,
"Designation" : "AC1; AC3",
"IP" : "123.456.78.9",
"Capacity" : 12,
}
],
"User" : [
{
"Number" : "EBBW396",
"Password" : "titi",
"Name" : "NDJO",
"Surname" : "Charles",
"Tel" : "06XXXXXX",
"isAdmin" : true
}
]
}
]
}
And i want to insert a new array embedded in "Test".
So i found my happiness here : https://docs.mongodb.com/getting-started/csharp/update/ AND How to use C# to insert document into existing embedded documents?
And i have write this code :
static void Main(string[] args)
{
IMongoClient client = new MongoClient("mongodb://10.194.157.199:27017");
IMongoDatabase database = client.GetDatabase("PINEA");
IMongoCollection<Product> collection = database.GetCollection<Product>("Product");
var filter = Builders<Product>.Filter.Eq("Test.Num_Test", "PU170017");
var meter = new Meter();
meter.Value= 12;
meter.Date = DateTime.Now;
var meterList = new List<Meter>();
meterList.Add(meter);
var update = Builders<Product>.Update.Push("Result", new Result
{
MeterList = meterList
});
var result = collection.UpdateOne(filter, update);
}
But nothing happens, nothing has added or modified. I miss something important but i don't understand what is it.
Finally, here are my classes:
class Result
{
public List<Meter> MeterList { get; set; }
public List<Problem> Problem { get; set; }
}
class Meter
{
public int? Value { get; set; }
public DateTime? Date { get; set; }
}
class Test
{
public string Num_Test { get; set; }
public DateTime? Date_Start { get; set; }
public List<Bench> Bench { get; set; }
public List<User> User { get; set; }
public List<Result> Result { get; set; }
}
class Product
{
public string Builder { get; set; }
public string Fammily { get; set; }
public string ProductName { get; set; }
public string ProductNumber { get; set; }
public List<Test> Test { get; set; }
}
To explain the context, I need to update the array "result" regularly and maintain data arborescence like that. After the end of the test, data aren't modify anymore.
PS : I'm still a student but I work part time
Thanks