```
  foreach ($dce_elements as $index => $dce_element) {
    $dce_uuid = $dce_element->getAttribute("ref-uuid");
    $dce_wrapper = _mica_import_find_or_create_node($dce_uuid, 'data_collection_event');
    $nid = $dce_wrapper->nid->value();
    if (empty($nid)) {
      $dce_wrapper->save();    
    }
    $wrapper->field_pop_dce[$index]->set($dce_wrapper->nid->value());
  }
```