code: private ThymeLeafTemplateImplementation getTemplateByURL(URL url) {
          Collection<ThymeLeafTemplateImplementation> list = registrations.keySet();
          for (ThymeLeafTemplateImplementation template : list) {
              if (template.getURL().sameFile(url)) {
                  return template;
              }
          }
          return null;
      }
docs: Gets the template object using the given url as backend.
  
  @param url the url
  @return the template object, {@literal null} if not found