code: def storage_class(self, value):
          
          if value not in self._STORAGE_CLASSES:
              raise ValueError("Invalid storage class: %s" % (value,))
          self._patch_property("storageClass", value)
docs: Set the storage class for the bucket.
  
          See https://cloud.google.com/storage/docs/storage-classes
  
          :type value: str
          :param value: one of "MULTI_REGIONAL", "REGIONAL", "NEARLINE",
                        "COLDLINE", "STANDARD", or "DURABLE_REDUCED_AVAILABILITY"