Issue #3065591 by Charlie ChX Negyesi, amateescu: Add a useful example to TranslatableInterface::addTranslation

core/lib/Drupal/Core/TypedData/TranslatableInterface.php

@@ -99,6 +99,11 @@ interface TranslatableInterface {
   /**
    * Adds a new translation to the translatable object.
    *
+   * To create a translation of an entity prefilled with the original data:
+   * @code
+   *   $entity->addTranslation($langcode, $entity->toArray())
+   * @endcode
+   *
    * @param string $langcode
    *   The language code identifying the translation.
    * @param array $values