src/Storage/Session.php
public function clear($uid = null) {
        $this->alloc();
        if ($uid) {
            return $this->session->offsetUnset($uid);
        }
        return $this->session->exchangeArray(array());
    }
public function clear($uid = null) {
        $this->alloc();
        if ($uid) {
            return $this->session->offsetUnset($uid);
        }
        return $this->session->exchangeArray(array());
    }
Clear datas with $uid key
@param mixed $uid
@return void