code: def _private_notes2marc(self, key, value):
      
      def _is_from_hal(value):
          return value.get('source') == 'HAL'
  
      if not _is_from_hal(value):
          return {
              '9': value.get('source'),
              'a': value.get('value'),
          }
  
      self.setdefault('595_H', []).append({'a': value.get('value')})
docs: Populate the ``595`` MARC key.
  
      Also populates the `595_H` MARC key through side effects.