public ReportTask AddTask()
{
ReportTask result = ReportTask.Create();
result.Name = Helper.GetUniqueName("Task", (from i in Tasks select i.Name).ToList());
ReportSource source = Sources.FirstOrDefault(i => i.IsDefault);
if (source == null) source = Sources[0];
result.SourceGUID = source.GUID;
result.Report = this;
result.SortOrder = Tasks.Count > 0 ? Tasks.Max(i => i.SortOrder) + 1 : 1;
Tasks.Add(result);
return result;
}