code: def get_bucket_acl(self, bucket):
          
          details = self._details(
              method=b"GET",
              url_context=self._url_context(bucket=bucket, object_name="?acl"),
          )
          d = self._submit(self._query_factory(details))
          d.addCallback(self._parse_acl)
          return d
docs: Get the access control policy for a bucket.