code: def get_acl(self, key_name='', headers=None, version_id=None):
           
          return self.get_acl_helper(key_name, headers, STANDARD_ACL)
docs: returns a bucket's acl. We include a version_id argument
             to support a polymorphic interface for callers, however, 
             version_id is not relevant for Google Cloud Storage buckets 
             and is therefore ignored here.