public OperationFuture<List<Server>> startMaintenance(GroupFilter groupFilter) {
        return serverService().startMaintenance(
            getServerSearchCriteria(groupFilter)
        );
    }
public OperationFuture < List < Server > > startMaintenance ( GroupFilter groupFilter ) { return serverService ( ) . startMaintenance ( getServerSearchCriteria ( groupFilter ) ) ; }
Start servers groups maintenance

@param groupFilter search servers criteria by group filter
@return OperationFuture wrapper for Server list