code: def bucket_policy_only_locked_time(self):
          
          bpo = self.get("bucketPolicyOnly", {})
          stamp = bpo.get("lockedTime")
          if stamp is not None:
              stamp = _rfc3339_to_datetime(stamp)
          return stamp
docs: Deadline for changing :attr:`bucket_policy_only_enabled` from true to false.
  
          If the bucket's :attr:`bucket_policy_only_enabled` is true, this property
          is time time after which that setting becomes immutable.
  
          If the bucket's :attr:`bucket_policy_only_enabled` is false, this property
          is ``None``.
  
          :rtype: Union[:class:`datetime.datetime`, None]
          :returns:  (readonly) Time after which :attr:`bucket_policy_only_enabled` will
                     be frozen as true.