Update drupal 8 node and save

update-d8-node-save

use Drupal\node\Entity\Node;

function _svv_tools_set_author() {
  $user = user_load_by_name('test');
  $query = \Drupal::entityQuery('node');
  $nids = $query->execute();
  dd($nids);
  foreach ($nids as $nid) {
    $node = Node::load($nid);
    $node->uid->value = $user->id();
    $node->save();
  }

}