public ZlibOutputStream(OutputStream os, int compressionLevel, int strategy, int encodingMode)
private ZlibOutputStream(OutputStream os, Deflater def)
  public ZlibOutputStream(OutputStream os,			  int compressionLevel,			  int strategy,			  int encodingMode)    throws IOException  {    this(os, createDeflater(compressionLevel, strategy, encodingMode));    _isGzip = (encodingMode == ZlibModule.FORCE_GZIP);    if (_isGzip)      _crc32 = new CRC32();  }