code: protected void doRestore(File backupFile) throws BackupException
     {
        if (!PrivilegedFileHelper.exists(backupFile))
        {
           LOG.warn("Nothing to restore for quotas");
           return;
        }
  
        ZipObjectReader in = null;
        try
        {
           in = new ZipObjectReader(PrivilegedFileHelper.zipInputStream(backupFile));
           quotaPersister.restoreWorkspaceData(rName, wsName, in);
        }
        catch (IOException e)
        {
           throw new BackupException(e);
        }
        finally
        {
           if (in != null)
           {
              try
              {
                 in.close();
              }
              catch (IOException e)
              {
                 LOG.error("Can't close input stream", e);
              }
           }
        }
  
        repairDataSize();
     }
docs: Restores content.