/**
* {@inheritdoc}
*/
public function form(array $form, FormStateInterface $form_state)
{
$replacement_styles = array_diff_key(image_style_options(), array($this->entity->id() => ''));
$form['replacement'] = array('#title' => $this->t('Replacement style'), '#type' => 'select', '#options' => $replacement_styles, '#empty_option' => $this->t('No replacement, just delete'));
return parent::form($form, $form_state);
}
