code: public function renderBlock($encodedBlock)
      {
          $values = json_decode($encodedBlock, true);
          if (!array_key_exists("type", $values) || null === $values["type"]) {
              return "";
          }
  
          $block = $this->serializer->deserialize($encodedBlock, BlockFactory::getBlockClass($values["type"]), 'json');
          $blockTemplate = $this->fetchTemplateBlock($block);
          $content = $this->templating->render($blockTemplate, array('block' => $block));
  
          // Looks for images
          $this->updateMediaFiles('src', $content);
  
          // Looks for files
          $this->updateMediaFiles('href', $content);
  
          return $content;
      }
docs: Renders a block from a encoded json content
  @param $encodedBlock
  
  @return string