public static SimpleFileSink withDefaults(String dir, String fileName) {
		return new SimpleFileSink(dir, fileName, true, DEFAULT_MODE);
	}
Return an instance of a SimpleFileSink given the directory and file to write to.  The file mode is binary and 
will be replaced if it already exists.
@param dir the directory where files should be written
@param fileName the name of the file to be written.
@return an instance of SimpleFileSink
spring-xd-test-fixtures/src/main/java/org/springframework/xd/test/fixtures/SimpleFileSink.java