protected void populateRepository() {
		List<String> shuffled = new ArrayList<String>(NUMBERS);
		Collections.shuffle(shuffled);
		for (String n : shuffled) {
			repo.save(n);
		}

	}
Subclasses must implement to init the repository.
spring-xd-analytics/src/test/java/org/springframework/xd/store/BaseRepositoryTests.java