lease_addition=self.apiserver.AddLeases(self.auth_root(),nodes,
lease_spec['slice'],lease_spec['t_from'],lease_spec['t_until'])
if lease_addition['errors']:
lease_addition=self.apiserver.AddLeases(self.auth_root(),nodes,
lease_spec['slice'],lease_spec['t_from'],lease_spec['t_until'])
if lease_addition['errors']: