/// <summary>
/// Create a new FilterDirectoryReader that filters a passed in DirectoryReader,
/// using the supplied SubReaderWrapper to wrap its subreader. </summary>
/// <param name="in"> the DirectoryReader to filter </param>
/// <param name="wrapper"> the SubReaderWrapper to use to wrap subreaders </param>
public FilterDirectoryReader(DirectoryReader @in, SubReaderWrapper wrapper)
: base(@in.Directory(), wrapper.Wrap(@in.GetSequentialSubReaders().OfType <AtomicReader>().ToList()))
{
this.@in = @in;
}