docs: public static String contentShowTagAction(
          I_CmsXmlContentContainer container,
          PageContext context,
          String element,
          Locale locale,
          boolean escape) {
  
          // get the current users OpenCms context
          CmsObject cms = CmsFlexController.getCmsObject(context.getRequest());
  
          // get loaded content from content container
          I_CmsXmlDocument xmlContent = container.getXmlDocument();
  
          if (CmsStringUtil.isEmpty(element)) {
              element = container.getXmlDocumentElement();
          } else {
              element = CmsXmlUtils.concatXpath(container.getXmlDocumentElement(), element);
          }
  
          String content;
          if (CmsMacroResolver.isMacro(element)) {
              // this is a macro, initialize a macro resolver
              String resourcename = CmsJspTagResourceLoad.getResourceName(cms, container);
              CmsMacroResolver resolver = CmsMacroResolver.newInstance().setCmsObject(cms).setJspPageContext(
                  context).setResourceName(resourcename).setKeepEmptyMacros(true);
              // resolve the macro
              content = resolver.resolveMacros(element);
          } else if (xmlContent == null) {
              // no XML content- no output
              content = null;
          } else {
  
              // determine the locale to display
              if (locale == null) {
                  // no locale was set, use default from parent tag (usually "contentload")
                  locale = container.getXmlDocumentLocale();
              }
              // now get the content element value to display
  
              if (xmlContent.hasValue(element, locale)) {
                  try {
                      // read the element from the content
                      content = xmlContent.getStringValue(cms, element, locale);
                  } catch (Exception e) {
                      LOG.error(Messages.get().getBundle().key(Messages.LOG_ERR_CONTENT_SHOW_1, element), e);
                      content = null;
                  }
              } else {
                  content = null;
              }
  
              // make sure that no null String is returned
              if (content == null) {
                  content = CmsMessages.formatUnknownKey(element);
              }
              if (escape) {
                  // HTML escape the value
                  content = CmsEncoder.escapeHtml(content);
              }
          }
  
          return content;
      }