@Test(expected = IllegalArgumentException.class)
	public void testDeleteNullString() {
		fieldValueCounterRepository.delete((String) null);
	}
Base tests for various implementations of {@link FieldValueCounterRepository}.

@author Eric Bottard
@author Mark Pollack
spring-xd-analytics/src/test/java/org/springframework/xd/analytics/metrics/AbstractFieldValueCounterRepositoryTests.java