public void addWindowFilter(String windowName, USSDFilter filter)
 {
     if (windowFilters.Keys.Contains(windowName))
     {
         windowFilters[windowName].Add(filter);
     }
     else
     {
         List <USSDFilter> filterList = new List <USSDFilter>();
         filterList.Add(filter);
         windowFilters[windowName] = filterList;
     }
 }
 public void addFilter(USSDFilter filter)
 {
     filters.Add(filter);
 }
 public void appendFilter(USSDFilter filter)
 {
     Filters.Add(filter);
 }