Google Cloud Messaging Unique Key

I've read in Google Cloud Messaging documentation that GCM key is unique per device and per application. If I uninstall and reinstall the application the key is always the same, ie

Solution 1:

No, the key (called Registration ID) may change after you uninstall and re-install the app.

The following scenario will cause the ID to change :

1. un-install the app
2. send a GCM message to the device several times, until GCM server realizes that the app was uninstalled from the device
3. re-install the app