protected function parseSort(string $sort, array &$sorts)
    {
        if (strlen(trim($sort)) === 0) {
            return;
        }
        if (substr($sort, 0, 1) == "[") {
            // it might be the ridiculous JSON ExtJS sort format
            $json = json_decode($sort);
            if (is_array($json)) {
                foreach ($json as $s) {
                    if (is_object($s)) {
                        $sorts[$s->property] = strcasecmp(self::DESC, $s->direction) !== 0;
                    }
                }
                return;
            }
        }
        if (substr($sort, -4) == ",asc") {
        // foo,asc
            $sorts[substr($sort, 0, strlen($sort) - 4)] = true;
        } elseif (substr($sort, -5) == ",desc") {
        // foo,desc
            $sorts[substr($sort, 0, strlen($sort) - 5)] = false;
        } elseif (substr($sort, -10) == ":ascending") {
        // foo:ascending
            $sorts[substr($sort, 0, strlen($sort) - 10)] = true;
        } elseif (substr($sort, -11) == ":descending") {
        // foo:descending
            $sorts[substr($sort, 0, strlen($sort) - 11)] = false;
        } else {
            foreach (explode(',', $sort) as $s) {
                if (substr($s, 0, 1) === '-') {
                // -foo
                    $sorts[substr($s, 1)] = false;
                } elseif (substr($s, 0, 1) === '+') {
                // +foo
                    $sorts[substr($s, 1)] = true;
                } else {
                // foo
                    $sorts[$s] = true;
                }
            }
        }
    }