/**
  * Returns a random string with alpha-numeric characters.
  *
  * @param integer $count Number of characters to generate
  * @param string $characters Allowed characters, defaults to alpha-numeric (a-zA-Z0-9)
  * @return string A random string
  */
 public static function generateRandomString($count, $characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
 {
     return \Security_Randomizer::getRandomString($count, $characters);
 }