See https://github.com/googleapis/python-storage/issues/451#issuecomment-871463430 The following headers should be used to populate the corresponding properties: | HTTP Header | Property | | ------------- | ------------- | | `ETag` | `etag` | | `x-goog-generation` | `generation` | | `x-goog-metageneration` | `metageneration` |