public void Thread_FindUpsertEngine_Test()
        {
            using (var file = new TempFile())
                using (var db = new LiteEngine(file.Filename))
                {
                    var tasks = new List <Task>();

                    for (var i = 0; i < 50; i++) // Change 1000 to whatever value spams it enough.
                    {
                        var ind = i % 50;

                        var tFind   = Task.Factory.StartNew(() => { db.FindById("col", BitConverter.GetBytes(ind)); });
                        var tUpsert = Task.Factory.StartNew(() => { db.Upsert("col", new BsonDocument {
                                { "_id", BitConverter.GetBytes(ind) }
                            }); });

                        tasks.AddRange(new[] { tFind, tUpsert });
                    }

                    Task.WaitAll(tasks.ToArray());
                }
        }