protected function startRenderBlock($blockName, $segmentText)
    {
        foreach ($this->plugins as $plugin) {
            $blockRenderList = $plugin->getBlockRenderList();
            if (in_array($blockName, $blockRenderList) === true) {
                echo $plugin->callBlockRenderStart($blockName, $segmentText);
                ob_start();
                return;
            }
        }
        throw new JigException("Block $blockName not known for starting block in plugins.");
    }