{% extends "base/class.php.twig" %}

{% block file_path %}
Drupal\{{module}}\Form\{{ entity_class }}DeleteForm.
{% endblock %}

{% block namespace_class %}
namespace Drupal\{{module}}\Form;
{% endblock %}

{% block use_class %}
use Drupal\Core\Entity\EntityConfirmFormBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;
{% endblock %}

{% block class_declaration %}
/**
 * Builds the form to delete a {{ entity_class }}.
 */
class {{ entity_class }}DeleteForm extends EntityConfirmFormBase
{% endblock %}

{% block class_methods %}
  /**
   * {@inheritdoc}
   */
  public function getQuestion() {
    return $this->t('Are you sure you want to delete %name?', array('%name' => $this->entity->label()));
  }

  /**
  * {@inheritdoc}
  */
  public function getCancelUrl() {
    return new Url('{{ entity_name }}.list');
  }

  /**
  * {@inheritdoc}
  */
  public function getConfirmText() {
    return $this->t('Delete');
  }

  /**
  * {@inheritdoc}
  */
  public function submit(array $form, FormStateInterface $form_state) {
    $this->entity->delete();
    drupal_set_message($this->t('Category %label has been deleted.', array('%label' => $this->entity->label())));
    $form_state->setRedirectUrl($this->getCancelUrl());
  }
{% endblock %}

{% extends "base/class.php.twig" %}

{% block file_path %}
Drupal\{{module}}\Form\{{ entity_class }}DeleteForm.
{% endblock %}

{% block namespace_class %}
namespace Drupal\{{module}}\Form;
{% endblock %}

{% block use_class %}
use Drupal\Core\Entity\EntityConfirmFormBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;
{% endblock %}

{% block class_declaration %}
/**
 * Builds the form to delete a {{ entity_class }}.
 */
class {{ entity_class }}DeleteForm extends EntityConfirmFormBase
{% endblock %}

{% block class_methods %}
  /**
   * {@inheritdoc}
   */
  public function getQuestion() {
    return $this->t('Are you sure you want to delete %name?', array('%name' => $this->entity->label()));
  }

  /**
  * {@inheritdoc}
  */
  public function getCancelUrl() {
    return new Url('{{ entity_name }}.list');
  }

  /**
  * {@inheritdoc}
  */
  public function getConfirmText() {
    return $this->t('Delete');
  }

  /**
  * {@inheritdoc}
  */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $this->entity->delete();
    drupal_set_message($this->t('Category %label has been deleted.', array('%label' => $this->entity->label())));
    $form_state->setRedirectUrl($this->getCancelUrl());
  }
{% endblock %}

Rename method form to formSubmit
Rename method form to formSubmit
