title: How to get auto generated id from Google Cloud DataStore
body: <p>The documentation <a href="https://cloud.google.com/datastore/docs/concepts/entities" rel="noreferrer">here</a> says that I can omit the numeric id of an entity and DataStore will assign one automatically.</p>
  
  <p>It however, does not say how to retrieve the auto generated id. How does one get it?</p>
  
  <p>Is it available in the response or do I have to make a query against some other fields to retrieve the entity again just so I can see its ID?</p>