src/Log/Engine/DatabaseLog.php
protected function _userId() {
        if ( array_key_exists('userId', $this->_context) ) {
            $userId = ($this->_context['userId']) ? (int) $this->_context['userId'] : null;
            unset($this->_context['userId']);
            return $userId;
        }

        if ( isset($_SESSION) && is_array($_SESSION) )
            return Hash::get($_SESSION, $this->config('userId'));

        return null;
    }
protected function _userId() {
        if ( array_key_exists('userId', $this->_context) ) {
            $userId = ($this->_context['userId']) ? (int) $this->_context['userId'] : null;
            unset($this->_context['userId']);
            return $userId;
        }

        if ( isset($_SESSION) && is_array($_SESSION) )
            return Hash::get($_SESSION, $this->config('userId'));

        return null;
    }
Get user_id
@return int