forgot this piece of code somehow

As mentioned in commit a0fb89e8d950f972170506508c2bbadf815c0708 getStructKey(src) can be used to enforce that a string Id object always has an Id set -- there's no purpose for a string
Id object to be "incomplete" as the datastore won't assign a random string value.
Merge remote-tracking branch 'origin/fixes' into merged

Conflicts:
	entity.go