/**
 * Implements hook_entity_prepare_view().
 */
function {{ machine_name }}_entity_prepare_view($entity_type_id, array $entities, array $displays, $view_mode) {
  // Load a specific node into the user object for later theming.
  if (!empty($entities) && $entity_type_id == 'user') {
    // Only do the extra work if the component is configured to be
    // displayed. This assumes a 'mymodule_addition' extra field has been
    // defined for the entity bundle in hook_entity_extra_field_info().
    $ids = [];
    foreach ($entities as $id => $entity) {
      if ($displays[$entity->bundle()]->getComponent('mymodule_addition')) {
        $ids[] = $id;
      }
    }
    if ($ids) {
      $nodes = mymodule_get_user_nodes($ids);
      foreach ($ids as $id) {
        $entities[$id]->user_node = $nodes[$id];
      }
    }
  }
}