private static File makeDir() {
		try {
			File dir = File.createTempFile("FileSource", "");
			dir.delete();
			dir.mkdirs();
			return dir;
		}
		catch (IOException e) {
			throw new IllegalStateException(e);
		}
	}
First make a temporary directory where our file will live.
spring-xd-test-fixtures/src/main/java/org/springframework/xd/test/fixtures/FileSource.java