From TODO: ``` python # TODO: Make sure that this makes sense. # An entity should have a key all the time (even if it's partial). ``` See [`datastore.entity.Entity.__repr__`](https://github.com/GoogleCloudPlatform/gcloud-python/blob/1f2aaf3606802f4f02eeb30e22e1082ef7f4594e/gcloud/datastore/entity.py#L210) for relevant code and #146 for some context. `git blame` output ``` dec0e7c6 (JJ Geewax 2014-01-28 15:15:40 -0500 210) # TODO: Make sure that this makes sense. ```