book_entity_type_build

book_entity_type_build(array &$entity_types)

function book_entity_type_build(array &$entity_types) {
  /** @var $entity_types \Drupal\Core\Entity\EntityTypeInterface[] */
  $entity_types['node']
  ->setFormClass('book_outline', 'Drupal\book\Form\BookOutlineForm')
    ->setLinkTemplate('book-outline-form', '/node/{node}/outline')
    ->setLinkTemplate('book-remove-form', '/node/{node}/outline/remove');
}