This file contains several functions which are marked as deprecated. The documentation tells you what you should use instead.
However, the thing the documentation tells you to use instead is *itself* deprecated! This needs to be fixed, so the advice is correct and up to date.
eg in entity_view()
* @return array
* A render array for the entity.
*
* @deprecated as of Drupal 8.0.x, will be removed before Drupal 9.0.0.
* Use the entity view builder's view() method for creating a render array:
* @code
* $view_builder = \Drupal::entityManager()->getViewBuilder($entity->getEntityTypeId());
* return $view_builder->view($entity, $view_mode, $langcode);
* @endcode
*
* @see \Drupal\Core\Entity\EntityManagerInterface::getViewBuilder()
* @see \Drupal\Core\Entity\EntityViewBuilderInterface::view()
*/
function entity_view(EntityInterface $entity, $view_mode, $langcode = NULL, $reset = FALSE) {entityManager() is itself deprecated -- https://api.drupal.org/api/drupal/core!lib!Drupal.php/function/Drupal%3A...
Also, the use of the @code tag here is broken -- see https://api.drupal.org/api/drupal/core!includes!entity.inc/function/enti...