File tempFile = File.createTempFile("weka", null);
File tempFile = File.createTempFile("weka", SerializedInstancesLoader.FILE_EXTENSION);
  public void addUndoPoint() throws Exception {        if (m_Instances != null) {      // create temporary file      File tempFile = File.createTempFile("weka", null);      tempFile.deleteOnExit();      ObjectOutputStream oos = 	new ObjectOutputStream(	new BufferedOutputStream(	new FileOutputStream(tempFile)));          oos.writeObject(m_Instances);      oos.flush();      oos.close();      // update undo file list      if (m_tempUndoFiles[m_tempUndoIndex] != null) {	// remove undo points that are too old	m_tempUndoFiles[m_tempUndoIndex].delete();      }      m_tempUndoFiles[m_tempUndoIndex] = tempFile;      if (++m_tempUndoIndex >= m_tempUndoFiles.length) {	// wrap pointer around	m_tempUndoIndex = 0;      }      m_UndoBut.setEnabled(true);    }  }