https://docs.cloud.google.com/appengine/docs/standard/python3/reference/services/bundled/google/appengine/datastore/datastore_stub_util/FillUsersInQuery
google.appengine.datastore.datastore_stub_util.FillUsersInQuery | App Engine standard environment |...
Fill in a synthetic user ID for all user properties in a set of filters.
app enginegoogleappenginedatastorestub