'write'::
Write a commit graph file based on the commits found in packfiles.
-Includes all commits from the existing commit graph file.
++
+With the `--stdin-packs` option, generate the new commit graph by
+walking objects only in the specified pack-indexes.
'read'::
$ git commit-graph write
------------------------------------------------
+* Write a graph file, extending the current graph file using commits
+* in <pack-index>.
++
+------------------------------------------------
+$ echo <pack-index> | git commit-graph write --stdin-packs
+------------------------------------------------
+
* Read basic information from the commit-graph file.
+
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