Swift_DependencyContainer::getInstance PHP Method

    public static function getInstance()
    {
        if (!isset(self::$_instance)) {
            self::$_instance = new self();
        }
        return self::$_instance;
    }

 /**
  * Checks if an email matches the current grammars
  * @param string $email
  */
 public static function email($email)
 {
     if (self::$grammar === null) {
         self::$grammar = Swift_DependencyContainer::getInstance()->lookup('mime.grammar');
     }
     return preg_match('/^' . self::$grammar->getDefinition('addr-spec') . '$/D', $email);
 }