/**
  * set the filters to be applied to the stream.
  *
  * @param filters The filters to set on this stream.
  * @throws IOException If there is an error clearing the old filters.
  */
 public void setFilters(COSBase filters) throws IOException {
   // should this be allowed?  Should this
   // propagate to all streams in the array?
   firstStream.setFilters(filters);
 }