public void addEntry( String filename, String extension ) throws IOException {
    // Default no-op behavior
  }
@Test
  public void testAddEntry() throws IOException {
    CompressionProvider provider = outStream.getCompressionProvider();
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    outStream = new DummyCompressionOS( out, provider );
    outStream.addEntry( null, null );
  }