public function getFixesForLevel($level)
    {
        if ($level == $this->levels[0]) {
            return array();
        }
        $activated_levels = array();
        for ($i = 1, $c = count($this->levels); $i < $c; $i++) {
            $activated_levels[] = $this->levels[$i];
            if ($this->levels[$i] == $level) {
                break;
            }
        }
        if ($i == $c) {
            trigger_error(
                'Tidy level ' . htmlspecialchars($level) . ' not recognized',
                E_USER_WARNING
            );
            return array();
        }
        $ret = array();
        foreach ($activated_levels as $level) {
            foreach ($this->fixesForLevel[$level] as $fix) {
                $ret[$fix] = true;
            }
        }
        return $ret;
    }