diff --git a/dulwich/cloud/gcs.py b/dulwich/cloud/gcs.py
index fbe49c58..11f9d689 100644
--- a/dulwich/cloud/gcs.py
+++ b/dulwich/cloud/gcs.py
@@ -1,80 +1,83 @@
 # object_store.py -- Object store for git objects
 # Copyright (C) 2021 Jelmer Vernooij <jelmer@jelmer.uk>
 #
 # Dulwich is dual-licensed under the Apache License, Version 2.0 and the GNU
 # General Public License as public by the Free Software Foundation; version 2.0
 # or (at your option) any later version. You can redistribute it and/or
 # modify it under the terms of either of these two licenses.
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
 # You should have received a copy of the licenses; if not, see
 # <http://www.gnu.org/licenses/> for a copy of the GNU General Public License
 # and <http://www.apache.org/licenses/LICENSE-2.0> for a copy of the Apache
 # License, Version 2.0.
 #
 
 
 """Storage of repositories on GCS."""
 
 from io import BytesIO
 import posixpath
 import tempfile
 
 from ..object_store import BucketBasedObjectStore
 from ..pack import PackData, Pack, load_pack_index_file
 
 
+# TODO(jelmer): For performance, read ranges?
+
+
 class GcsObjectStore(BucketBasedObjectStore):
 
     def __init__(self, bucket, subpath=''):
         super(GcsObjectStore, self).__init__()
         self.bucket = bucket
         self.subpath = subpath
 
     def __repr__(self):
         return "%s(%r, subpath=%r)" % (
             type(self).__name__, self.bucket, self.subpath)
 
     def _remove_pack(self, name):
         self.bucket.delete_blobs([
             posixpath.join(self.subpath, name) + '.' + ext
             for ext in ['pack', 'idx']])
 
     def _iter_pack_names(self):
         packs = {}
         for blob in self.bucket.list_blobs(prefix=self.subpath):
             name, ext = posixpath.splitext(posixpath.basename(blob.name))
             packs.setdefault(name, set()).add(ext)
         for name, exts in packs.items():
             if exts == set(['.pack', '.idx']):
                 yield name
 
     def _load_pack_data(self, name):
         b = self.bucket.blob(posixpath.join(self.subpath, name + '.pack'))
         f = tempfile.SpooledTemporaryFile()
         b.download_to_file(f)
         f.seek(0)
         return PackData(name + '.pack', f)
 
     def _load_pack_index(self, name):
         b = self.bucket.blob(posixpath.join(self.subpath, name + '.idx'))
         f = tempfile.SpooledTemporaryFile()
         b.download_to_file(f)
         f.seek(0)
         return load_pack_index_file(name + '.idx', f)
 
     def _get_pack(self, name):
         return Pack.from_lazy_objects(
             lambda: self._load_pack_data(name),
             lambda: self._load_pack_index(name))
 
     def _upload_pack(self, basename, pack_file, index_file):
         idxblob = self.bucket.blob(posixpath.join(self.subpath, basename + '.idx'))
         datablob = self.bucket.blob(posixpath.join(self.subpath, basename + '.pack'))
         idxblob.upload_from_file(index_file)
         datablob.upload_from_file(pack_file)