/**
  * Asserts that this fixture's <code>{@link VFSJFileChooser}</code> is visible.
  *
  * @return this fixture.
  * @throws AssertionError if this fixture's <code>VFSJFileChooser</code> is not visible.
  */
 public VFSJFileChooserFixture<FileObject> requireVisible() {
   driver.requireVisible(target);
   return this;
 }