Since I strongly believe that the business logic to get the account belongs to the Authentication manager I will add a proxy method to get the account from `RestfulEntityInterface`.
```php
  /**
   * Proxy method to get the account from the authenticationManager.
   *
   * @return \stdClass
   *   The user object.
   */
  public function getAccount() {
    return $this->authenticationManager->getAccount();
  }
```