Default options form that provides the label widget that all fields should have.
Overrides Link::buildOptionsForm
public function buildOptionsForm(&$form, &$form_state) {
parent::buildOptionsForm($form, $form_state);
$form['destination'] = array(
'#type' => 'checkbox',
'#title' => t('Use destination'),
'#description' => t('Add destination to the link'),
'#default_value' => $this->options['destination'],
'#fieldset' => 'more',
);
}