@Test
	public void testFilter() {
		String filterContent = "good";
		stream(sources.http() + XD_DELIMITER + " filter --expression=payload=='" + filterContent + "' " + XD_DELIMITER
				+ sinks.file());
		sources.httpSource().postData(filterContent);
		assertValid(filterContent, sinks.file());
		assertReceived(1);
	}
Evaluates that a single data entry of "good" is not allowed past the filter and stored in a file..
spring-xd-integration-test/src/test/java/org/springframework/xd/integration/test/ProcessorTest.java