FSClient.Call.ClearCallsFromHistory C# (CSharp) Méthode

        public static void ClearCallsFromHistory()
        {
            foreach (var call in calls.ToArray())
                call.RemoveCallFromHistory();
        }

 private void btnClearAllCalls(object sender, RoutedEventArgs e)
 {
     Call.ClearCallsFromHistory();
 }