@Override
			public void test(Message<?> message) throws MessagingException {
				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