@Override
			public void test(Message<?> message) throws MessagingException {
				if (message.getPayload() instanceof FileMarker) {
					final FileMarker fileMarker = (FileMarker) message.getPayload();
					if (FileMarker.Mark.START.equals(fileMarker.getMark())) {
						startFileMarker = fileMarker;
					}
					else if (FileMarker.Mark.END.equals(fileMarker.getMark())) {
						endFileMarker = fileMarker;
					}
				}
				else {
					assertTrue("Extected a String", message.getPayload() instanceof String);
					assertEquals("foo", message.getPayload());
					assertEquals("foo1.txt", message.getHeaders().get(FileHeaders.FILENAME, String.class));
					counter.incrementAndGet();
				}
			}
@author David Turanski
@author Gunnar Hillert
@author Gary Russell
spring-xd-dirt/src/test/java/org/springframework/xd/dirt/stream/FileSourceModuleTests.java