node_save example

  $limit = 5;

  // With each pass through the callback, retrieve the next group of nids.   $result = $database->queryRange("SELECT [nid] FROM {node} WHERE [nid] > :nid ORDER BY [nid] ASC", 0, $limit, [':nid' => $context['sandbox']['current_node']]);
  foreach ($result as $row) {

    // Here we actually perform our processing on the current node.     $node_storage->resetCache([$row['nid']]);
    $node = $node_storage->load($row['nid']);
    $node->value1 = $options1;
    $node->value2 = $options2;
    node_save($node);

    // Store some result for post-processing in the finished callback.     $context['results'][] = $node->title;

    // Update our progress information.     $context['sandbox']['progress']++;
    $context['sandbox']['current_node'] = $node->nid;
    $context['message'] = t('Now processing %node', ['%node' => $node->title]);
  }

  // Inform the batch engine that we are not finished,