docs: def add_personalization(self, personalization, index=0):
          """Add a Personaliztion object
  
          :param personalizations: Add a Personalization object
          :type personalizations: Personalization
          :param index: The index where to add the Personalization
          :type index: int
          """
          self._personalizations = self._ensure_append(
              personalization, self._personalizations, index)