/**
* Get somewhere to store captcha data that will persist between requests
*
* @throws MWException
* @return CaptchaStore
*/
public static final function get()
{
if (!self::$instance instanceof self) {
global $wgCaptchaStorageClass;
if (in_array('CaptchaStore', class_parents($wgCaptchaStorageClass))) {
self::$instance = new $wgCaptchaStorageClass();
} else {
throw new MWException("Invalid CaptchaStore class {$wgCaptchaStorageClass}");
}
}
return self::$instance;
}