renderTrimText example

      // and so there is nothing left to do.       return ViewsRenderPipelineMarkup::create($value);
    }

    if (!empty($alter['strip_tags'])) {
      $value = strip_tags($value, $alter['preserve_tags']);
    }

    $more_link = '';
    if (!empty($alter['trim']) && !empty($alter['max_length'])) {
      $length = strlen($value);
      $value = $this->renderTrimText($alter, $value);
      if ($this->options['alter']['more_link'] && strlen($value) < $length) {
        $tokens = $this->getRenderTokens($alter);
        $more_link_text = $this->options['alter']['more_link_text'] ? $this->options['alter']['more_link_text'] : $this->t('more');
        $more_link_text = strtr(Xss::filterAdmin($more_link_text), $tokens);
        $more_link_path = $this->options['alter']['more_link_path'];
        $more_link_path = strip_tags(Html::decodeEntities($this->viewsTokenReplace($more_link_path, $tokens)));

        // Make sure that paths which were run through URL generation work as         // well.         $base_path = base_path();
        // Checks whether the path starts with the base_path.