League\CommonMark\Block\Renderer\DocumentRenderer::render PHP Метод

    public function render(AbstractBlock $block, ElementRendererInterface $htmlRenderer, $inTightList = false)
    {
        if (!$block instanceof Document) {
            throw new \InvalidArgumentException('Incompatible block type: ' . get_class($block));
        }
        $wholeDoc = $htmlRenderer->renderBlocks($block->children());
        return $wholeDoc === '' ? '' : $wholeDoc . "\n";
    }