Core 'language' datatype has wrong @var types

$ drupal-check -a core/lib/Drupal/Core/TypedData/Plugin/DataType/Language.php
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  Line   Language.php                                                           
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  32     Property Drupal\Core\TypedData\Plugin\DataType\Language::$language     
         has unknown class Drupal\Core\Language as its type.                    
         💡 Learn more at https://phpstan.org/user-guide/discovering-symbols     
  40     Property Drupal\Core\TypedData\Plugin\DataType\Language::$language     
         (Drupal\Core\Language) in isset() is not nullable.                     
  41     Property Drupal\Core\TypedData\Plugin\DataType\Language::$language     
         (Drupal\Core\Language) does not accept                                 
         Drupal\Core\Language\LanguageInterface|null.                           
  43     Method Drupal\Core\TypedData\Plugin\DataType\Language::getValue()      
         should return Drupal\Core\Language\LanguageInterface|null but returns  
         Drupal\Core\Language.                                                  
  62     Property Drupal\Core\TypedData\Plugin\DataType\Language::$language     
         (Drupal\Core\Language) does not accept null.                           
  82     Property Drupal\Core\TypedData\Plugin\DataType\Language::$id (string)  
         in isset() is not nullable.                                            
  85     Property Drupal\Core\TypedData\Plugin\DataType\Language::$language     
         (Drupal\Core\Language) in isset() is not nullable.                     
  86     Call to method getId() on an unknown class Drupal\Core\Language.       
         💡 Learn more at https://phpstan.org/user-guide/discovering-symbols     
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 [ERROR] Found 8 errors