public function getBlockRenderer(BlockInterface $block)
    {
        $type = $block->getType();

        $name = isset($this->blockRenderers[$type]) ? $this->blockRenderers[$type] : $this->defaultRenderer;
        $service = $this->getRendererService($name);

        if (!$service instanceof RendererInterface) {
            throw new \RuntimeException(sprintf('The service "%s" is not an exception renderer', $name));
        }

        return $service;
    }