protected void verifyStreamCreated(String streamName) throws InterruptedException {
		long expiry = System.currentTimeMillis() + STATE_TRANSITION_TIMEOUT;
		while (!streamExists(streamName) && System.currentTimeMillis() < expiry) {
			Thread.sleep(500);
		}
		assertTrue(streamExists(streamName));
	}
Assert that the given stream has been created.

@param streamName  name of stream to verify
spring-xd-distributed-test/src/test/java/org/springframework/xd/distributed/test/AbstractDistributedTests.java