docs: def _render_email_placeholder(request, email_template, base_url, context):
      """
      Internal rendering of the placeholder/contentitems.
  
      This a simple variation of render_placeholder(),
      making is possible to render both a HTML and text item in a single call.
      Caching is currently not implemented.
  
      :rtype: fluentcms_emailtemplates.rendering.EmailBodyContent
      """
      placeholder = email_template.contents
      items = placeholder.get_content_items(email_template)
  
      if not items:  # NOTES: performs query
          # There are no items, fetch the fallback language.
          language_code = fc_appsettings.FLUENT_CONTENTS_DEFAULT_LANGUAGE_CODE
          items = placeholder.get_content_items(email_template, limit_parent_language=False).translated(language_code)
  
      html_fragments = []
      text_fragments = []
  
      for instance in items:
          plugin = instance.plugin
          html_part = _render_html(plugin, request, instance, context)
          text_part = _render_text(plugin, request, instance, context, base_url)
          html_fragments.append(html_part)
          text_fragments.append(text_part)
  
      html_body = u"".join(html_fragments)
      text_body = u"".join(text_fragments)
  
      return EmailBodyContent(text_body, html_body)