code: def default_kms_key_name(self, value):
          
          encryption_config = self._properties.get("encryption", {})
          encryption_config["defaultKmsKeyName"] = value
          self._patch_property("encryption", encryption_config)
docs: Set default KMS encryption key for objects in the bucket.
  
          :type value: str or None
          :param value: new KMS key name (None to clear any existing key).