code: def copyright2marc(self, key, value):
      
      E_MAP = {
          'publication': 'Article',
      }
  
      e_value = value.get('material')
  
      return {
          'd': value.get('holder'),
          'e': E_MAP.get(e_value),
          'f': value.get('statement'),
          'g': value.get('year'),
          'u': value.get('url'),
      }
docs: Populate the ``542`` MARC field.