Default options form that provides the label widget that all fields should have.
Overrides AreaPluginBase::buildOptionsForm
public function buildOptionsForm(&$form, &$form_state) {
parent::buildOptionsForm($form, $form_state);
$form['content'] = array(
'#type' => 'textarea',
'#default_value' => $this->options['content'],
'#rows' => 6,
);
// Add tokenization form elements.
$this
->tokenForm($form, $form_state);
}