public SimpleTailSource tail(int delayInMillis, String fileName) {
		return new SimpleTailSource(delayInMillis, fileName);
	}
Construct a new SimpleTailSource with the the provided file name and delay

@param delayInMillis on platforms that don't wait for a missing file to appear, how often (ms) to look for the
file.
@param fileName the absolute path of the file to tail
@return a tail source
spring-xd-integration-test/src/main/java/org/springframework/xd/integration/fixtures/Sources.java