public IEnumerator <KeyValuePair <string, TValue> > GetEnumerator()
 {
     foreach (var(p, value) in control.properties)
     {
         var pg = p as GroupedDotvvmProperty;
         if (pg != null && pg.PropertyGroup == group)
         {
             yield return(new KeyValuePair <string, TValue>(pg.GroupMemberName, (TValue)control.EvalPropertyValue(p, value)));
         }
     }
 }