r::set PHP Method

    static function set($key, $value = null)
    {
        $data = self::data();
        if (is_array($key)) {
            self::$_ = array_merge($data, $key);
        } else {
            self::$_[$key] = $value;
        }
    }

 public function testSet()
 {
     r::set('testvar', 'testvalue');
     $this->assertEquals('testvalue', r::get('testvar'));
 }