code: private final CompiledST loadTemplateResource(String prefix, String unqualifiedFileName) {
          //if (resourceRoot == null) return null;
          //return loadTemplate(resourceRoot, prefix, unqualifiedFileName);
          if (resourceRoots.isEmpty()) return null;
          CompiledST template = null;
          for (URL resourceRoot : resourceRoots) {
              if ((template = loadTemplate(resourceRoot, prefix, unqualifiedFileName)) != null)
                  return template;
          }
          return null;
      }
docs: Loads from a jar or similar resource if the template could not be found
  directly on the filesystem.