public void testRefreshAfterFileUpdate() throws Exception {
IDMigrator migrator = new FileIDMigrator(testFile, 0L);
/* call a method to make sure the original file is loaded */
long dogAsLong = migrator.toLongID("dog");
migrator.toStringID(dogAsLong);
/* change the underlying file,
* we have to wait at least a second to see the change in the file's lastModified timestamp */
Thread.sleep(2000L);
writeLines(testFile, UPDATED_STRING_IDS);