public void ApplyFilter(DateTime startDate, DateTime endDate)
        {
            var costs = DbWorker.Current.GetCosts().Where(c => DateUtility.GetLocalTimeFromUTCMilliseconds(c.Date) > startDate && DateUtility.GetLocalTimeFromUTCMilliseconds(c.Date) < endDate);

            Datas.Clear();

            foreach (var category in MainViewModel.Current.Categories)
            {
                var tempCosts = costs.Where(c => c.CategoryId == category.Id);

                if (tempCosts.Count() > 0)
                {
                    double sumInCategory = tempCosts.Sum(c => c.Cost);
                    Datas.Add(
                        new DataDiagramViewModel
                    {
                        Value = (sumInCategory / AllCosts) * 100,
                        Color = category.Color,
                        Title = category.Title
                    });
                }
            }
        }