/// <summary>
/// Creates a new duplicate of a stream.
/// </summary>
/// <param name="source">source of the duplicate</param>
internal DuplicateStream(Stream source)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
this.source = DuplicateStream.OriginalStream(source);
}
/// <summary>
/// Retrieves the original stream from a possible duplicate stream.
/// </summary>
/// <param name="stream">Possible duplicate stream.</param>
/// <returns>If the stream is a DuplicateStream, returns
/// the duplicate's source; otherwise returns the same stream.</returns>
internal static Stream OriginalStream(Stream stream)
{
DuplicateStream dupStream = stream as DuplicateStream;
return(dupStream != null ? dupStream.Source : stream);
}