/**
  * Class constructor.
  *
  * @param Array $options
  *   Associative array of adapter options.
  * @return void
  *   Returns nothing; it's a constructor.
  * @see self::setOptions()
  * @see Base::__construct()
  */
 public function __construct(array $options = array())
 {
     // Versions of PHP < 5.3.7 only support the 2a identifier
     if (version_compare(PHP_VERSION, '5.3.7', '<')) {
         $this->_identifier = '2a';
         $this->_validIdentifiers = array('2a');
     }
     parent::__construct($options);
 }