public function meta($tpl, $outputtype = '', $trusted = true)
    {
        if (in_array($tpl, $this->processedMeta)) {
            // we want to process meta only one time, when a template is included
            // several time in an other template, or, more important, when a template
            // is included in a recursive manner (in this case, it did cause infinite loop, see #1396).
            return $this->_meta;
        }
        $this->processedMeta[] = $tpl;
        $md = $this->getTemplate($tpl, $outputtype, $trusted);

        $fct = 'template_meta_'.$md;
        $fct($this);

        return $this->_meta;
    }