private void GetOperators()
 {
     DeserializeXml dx = new DeserializeXml();
     Trainees = dx.DeserializePersons();
     DateTreeView dv = new DateTreeView();
     if (Trainees != null)
     {
         var listOperator = dv.GetDates(Trainees);
         BindTree(listOperator);
     }
 }
        // Get Operators
        private void GetOperators()
        {
            DeserializeXml dx = new DeserializeXml();
            Operators = dx.DeserializePersons();
            DateTreeView dv = new DateTreeView();

            if (Operators != null)
            {
                var dateList = dv.GetDates(Operators);
                BindTree(dateList);
            }
        }