/**
   * Bug 72214: [Preferences] IAE when opening project preferences
   *
   * @see "http://bugs.eclipse.org/bugs/show_bug.cgi?id=72214"
   */
  public void testBug72214() throws CoreException, BackingStoreException {
    // Remove JavaCore instance prefs
    JavaModelManager manager = JavaModelManager.getJavaModelManager();
    IEclipsePreferences preferences = manager.getInstancePreferences();
    int size = JavaCore.getOptions().size();
    preferences.removeNode();

    // verify that JavaCore preferences have been reset
    assertFalse(
        "JavaCore preferences should have been reset",
        preferences == manager.getInstancePreferences());
    assertEquals(
        "JavaCore preferences should have been resotred!", size, JavaCore.getOptions().size());
  }
 @Override
 protected void doDelete(HttpServletRequest req, HttpServletResponse resp)
     throws ServletException, IOException {
   IEclipsePreferences node = getNode(req, resp, false);
   if (node == null) {
     // should not fail on delete when resource doesn't exist
     resp.setStatus(HttpServletResponse.SC_NO_CONTENT);
     return;
   }
   String key = req.getParameter("key");
   try {
     // if a key is specified write that single value, otherwise write the entire node
     if (key != null) node.remove(key);
     else node.removeNode();
     prefRoot.flush();
     resp.setStatus(HttpServletResponse.SC_NO_CONTENT);
   } catch (Exception e) {
     handleException(
         resp, NLS.bind("Failed to retrieve preferences for path {0}", req.getPathInfo()), e);
     return;
   }
 }