code: public static boolean isWebjar(Extension extension)
      {
          // Ideally webjar extensions should have "webjar" type
          if (extension.getType().equals(WEBJAR)) {
              return true;
          }
  
          ///////////////////////////////
          // But it's not the case for:
  
          // ** webjar.org releases (i.e. most of the webjars). We assume "org.webjars:*" id means it's a webjar
          if (StringUtils.startsWithAny(extension.getId().getId(), "org.webjars:", "org.webjars.")) {
              return true;
          }
          // ** contrib extensions which support version of XWiki older than 9.0RC1. We support a custom property which
          // does not have any effect on older versions of XWiki
          if (JarExtensionHandler.WEBJAR.equals(extension.getProperty(JarExtensionHandler.PROPERTY_TYPE))) {
              return true;
          }
  
          return false;
      }
docs: Find of the passes extension if a webjar.
  
  @param extension the extension to test
  @return true of the passed extension is a webjar, false otherwise
  @since 9.0RC1