code: def _update_prefixes(self, refresh=True):
      if self._prefixes and not refresh:
          return
      prefixes = (
          (config, self._get_prefix_from_bucket_config(config))
          for config in self._buckets
      )
      self._prefixes = sorted(prefixes, key=itemgetter(1), reverse=True)
  
imports: import abc
  import warnings
  from copy import copy
  from operator import itemgetter
  from os import getenv
  import furl
  import six
  from attr import attrib, attrs
label_desc: Use image node_id 2 for calling the BaseBucketConfigurations obj's underlying member method code with example usage: obj._update_prefixes(refresh) without return types