Zend\Diactoros\Uri::filterQuery PHP Метод

    private function filterQuery($query)
    {
        if (!empty($query) && strpos($query, '?') === 0) {
            $query = substr($query, 1);
        }
        $parts = explode('&', $query);
        foreach ($parts as $index => $part) {
            list($key, $value) = $this->splitQueryValue($part);
            if ($value === null) {
                $parts[$index] = $this->filterQueryOrFragment($key);
                continue;
            }
            $parts[$index] = sprintf('%s=%s', $this->filterQueryOrFragment($key), $this->filterQueryOrFragment($value));
        }
        return implode('&', $parts);
    }