public function children($node) {
    $query = $this->node->newQuery();

    $query->where($this->node->getQualifiedParentColumnName(), '=', $node->getKey());

    // We must also add the scoped column values to the query to compute valid
    // left and right indexes.
    foreach($this->scopedAttributes($node) as $fld => $value)
      $query->where($this->qualify($fld), '=', $value);

    $query->orderBy($this->node->getQualifiedLeftColumnName());
    $query->orderBy($this->node->getQualifiedRightColumnName());
    $query->orderBy($this->node->getQualifiedKeyName());

    return $query->get();
  }