private void ListenToEvents(IListenable <int> collection, EventTypes events)
{
if (events.HasFlag(Changed))
{
collection.CollectionChanged += _changed;
}
if (events.HasFlag(Cleared))
{
collection.CollectionCleared += _cleared;
}
if (events.HasFlag(Removed))
{
collection.ItemsRemoved += _removed;
}
if (events.HasFlag(Added))
{
collection.ItemsAdded += _added;
}
if (events.HasFlag(Inserted))
{
collection.ItemInserted += _inserted;
}
if (events.HasFlag(RemovedAt))
{
collection.ItemRemovedAt += _removedAt;
}
}