code: private RollingUpdateOp forceRollingUpdateUndeploy(final ZooKeeperClient client,
                                                       final RollingUpdateOpFactory opFactory,
                                                       final DeploymentGroup deploymentGroup,
                                                       final String host) {
      return rollingUpdateUndeploy(client, opFactory, deploymentGroup, host, false);
    }
docs: forceRollingUpdateUndeploy is used to undeploy jobs from hosts that have been removed from the
  deployment group. It disables the 'skipRedundantUndeploys' flag, which disables the
  redundantDeployment() check.