private function traitAlias($trait_method_reference) {
    $node = new TraitAliasNode();
    $node->addChild($trait_method_reference, 'traitMethodReference');
    $this->mustMatch(T_AS, $node);
    if ($trait_modifier = $this->tryMatchToken(self::$visibilityTypes)) {
      $node->addChild($trait_modifier, 'visibility');
      $this->tryMatch(T_STRING, $node, 'alias');
      $this->endStatement($node);
      return $node;
    }
    $this->mustMatch(T_STRING, $node, 'alias');
    $this->endStatement($node);
    return $node;
  }