static String getRandomCountry() {
      int index = RANDOM.nextInt(COUNTRY.size());
      return COUNTRY.get(index);
    }
A mock member decorator service that introduces delay to the member decorate call for illustrating async APIs
use in high level application. In real world, this component would correspond to a component that makes remote
calls.
samza-test/src/main/java/org/apache/samza/example/AsyncApplicationExample.java