code: private OutputStream initializeSource()
      {
      try
        {
        PipedOutputStream pipeOut = new PipedOutputStream();
        PipedInputStream pipeIn = new PipedInputStream( pipeOut);
  
        filterInput_ = pipeIn;
        return new FilterSourceStream( pipeOut);
        }
      catch( Exception e)
        {
        throw new RuntimeException( "Can't initialize source stream", e);
        }
      }
docs: Initializes the source for filter input.