code: @Override
  	public InputStream getInputStream(String fileName) throws IOException {
  		InputStream inputStream = null;
  		if (fileExists(fileName)) {
  			String extension = getExtension(fileName);
  
  			if (isExternalSupported(extension)) {
  				inputStream = startExternal(fileName);
  			} else if (isInternalSupported(extension)) {
  				inputStream = internalSupport.get(extension).getInputStream(
  						fileName);
  			} else {
  				inputStream = getDefault(fileName);
  			}
  		}
  		return inputStream;
  	}
docs: Creates a InputStream where the unpacked data could be read from.
  Internal GZip and BZip2 archive formats are supported. The list archive
  formats can be increased with settings file decompressor.xml. Thereby
  <ul>
  <li>key is the archive extension</li>
  <li>value is the external command. The archive file should be specified
  with an place holder <code>UniversalDecompressor.FILEPLACEHOLDER</code></li>
  </ul>
  External decompression utilities are in preference to the internal. If
  there is nether external nor internal possibilities to unpack the file -
  the standard <code>FileInputSteam</code> will be returned
  
  @see UniversalDecompressor