/**
  * Tears down test environment.
  *
  * @throws Exception to JUnit
  */
 protected void tearDown() throws Exception {
   TestHelper.clearConfig();
   mapping = null;
   graphNode = null;
   usmb = null;
   node = null;
   connector = null;
 }
  /**
   * Initialization for all tests here.
   *
   * @throws Exception exception to JUnit.
   */
  protected void setUp() throws Exception {
    TestHelper.clearConfig();
    cm = ConfigManager.getInstance();

    // load XML file used to creat TagOptionManager.
    cm.add(CONFIG_FILE);
    parent = new DefaultTagEditor(NAMESPACE);
    element = new OperationImpl();
    parent.setTarget(element);
    tagTable = new DefaultTagTableModel(parent);
  }