code: public static function getToken($token_name = self::TOKEN_NAME)
  	{
  		if (empty($_SESSION[$token_name])) {
  			static::generateToken($token_name);
  		}
  
  		return $_SESSION[$token_name];
  	}
docs: Get the token.  If it's not defined, this will go ahead and generate one.
  
  @param string $token_name - defaults to the default token name
  @return string