@VisibleForTesting
  List<URL> getUrls(Config udfConfig) {
    String urls = udfConfig.getOrDefault(CONFIG_RESOURCE_URLS, "");
    List<URL> urlList = new ArrayList<>();
    if (!urls.isEmpty()) {
      for (String url : urls.split(",")) {
        try {
          urlList.add(new URL(url));
        } catch (MalformedURLException e) {
          LOG.error("Exception occurred when loading url: {}", url, e);
        }
      }
    }
    return urlList;
  }
An UDF resolver implementation that uses reflection to discover the subtypes
of the {@link SamzaSqlUdf} from the classpath. Performs the validation to
ensure that all subtypes of {@link SamzaSqlUdf} extend and implement the
method annotated with {@link SamzaSqlUdfMethod}.
samza-sql/src/main/java/org/apache/samza/sql/udf/ReflectionBasedUdfResolver.java