FluidTYPO3\Vhs\ViewHelpers\Page\HeaderViewHelper::render PHP Method

    public function render()
    {
        if ('BE' === TYPO3_MODE) {
            return;
        }
        $content = $this->getContent();
        $name = $this->getName();
        $overwrite = $this->getOverwrite();
        if (true === isset($GLOBALS['TSFE']->additionalHeaderData[$name]) && false === $overwrite) {
            return;
        }
        $GLOBALS['TSFE']->additionalHeaderData[$name] = $content;
    }