/**
     * Set the string value in argument as value of the key.
     *
     * @param   string  $key
     * @param   string  $value
     * @param   int   $timeout [optional] Calling setex() is preferred if you want a timeout.
     * @return  bool    TRUE if the command is successful.
     * @link    http://redis.io/commands/set
     * @example $redis->set('key', 'value');
     */
    public function set( $key, $value, $timeout = 0 ) {}