public TransformingNotifyingEnumerable(INotifyingEnumerable <THost> host, Func <THost, T> converter)
 {
     this.host      = host;
     this.converter = converter;
 }
 public ReadOnlyNotifyingCollection(INotifyingEnumerable <T> hostedNotifyingCollection)
 {
     this.hostedNotifyingCollection = hostedNotifyingCollection;
     this.hostedNotifyingCollection.EnumerationChanged += new EventHandler <EnumerationChangedEventArgs <T> >(this.HostedNotifyingCollection_EnumerationChanged);
 }