@After
	public void tearDown() {
		if (singleNodeApplication != null) {
			singleNodeApplication.close();
		}
		singleNodeApplication = null;
		if (shell != null) {
			shell.stop();
		}
		shell = null;
	}
Abstract Spark streaming test class which can be extended to run against multiple XD transport.

@author Ilayaperumal Gopinathan
spring-xd-spark-streaming-tests/src/test/java/org/springframework/xd/spark/streaming/AbstractSparkStreamingTests.java