public void testRemoveParentNode() throws BackingStoreException {
    assertNull(storage.toFolder());
    assertNull(storage.toPropertiesFile());

    Preferences subnode = pref.node("subnode");
    assertNull(storage.toFolder());
    assertNull(storage.toPropertiesFile());
    subnode.put("key", "value");
    subnode.flush();
    assertNotNull(storage.toFolder());
    assertNull(storage.toPropertiesFile());
    subnode.removeNode();
    pref.flush();
    assertNull(storage.toPropertiesFile());
    assertNull(storage.toFolder());
    assertFalse(storage.existsNode());
  }
  @RandomlyFails // FSException: Invalid lock (from flush)
  public void testRemoveNode() throws BackingStoreException {
    assertNull(storage.toFolder());
    assertNull(storage.toPropertiesFile());

    pref.put("key", "value");
    pref.node("subnode").put("key", "value");
    pref.flush();
    assertNotNull(storage.toPropertiesFile());
    assertNotNull(storage.toFolder());
    pref.removeNode();
    pref.flush();
    assertNull(storage.toPropertiesFile());
    assertNull(storage.toFolder());
    assertFalse(storage.existsNode());
    pref.sync();
  }