/*
   * (non-Javadoc)
   * @see org.eclipse.ui.plugin.AbstractUIPlugin#stop(org.osgi.framework.BundleContext)
   */
  @Override
  public void stop(BundleContext context) throws Exception {

    plugin = null;
    super.stop(context);
  }
  /*
   * (non-Javadoc)
   * @see org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.BundleContext)
   */
  @Override
  public void start(BundleContext context) throws Exception {

    super.start(context);
    plugin = this;
  }