int in the future, the backup manager then calls
your backup agent's <code><a href="../../reference/android/app/backup/BackupAgent.html#onBackup(android.os.ParcelFileDescriptor, android.app.backup.BackupDataOutput, android.os.ParcelFileDescriptor)">onBackup()</a></code> method.  You can make
the call whenever your data has changed, without having to worry about causing
excessive network activity.  If you request a backup twice before a backup
occurs, the backup only occurs once.</p>


<h2 id="restore">Resto