### Question:
DefaultStageService implements StageService { @Override public void save(StageStatus status) { Preferences node = Preferences.userRoot().node(STAGE_PATH); try { node.put(STAGE_STATUS_KEY, JSON.std.asString(status)); LOG.trace("Stage status saved {}", status); } catch (IOException e) { LOG.error("Unable to increment modules usage statistics", e); } }  @Override void save(StageStatus status); @Override StageStatus getLatestStatus(); @Override void clear();  }### Answer:
@Test public void save() throws JSONObjectException, IOException { StageStatus status = new StageStatus(10, 20, 100, 200); victim.save(status); StageStatus storedStatus = JSON.std.beanFrom(StageStatus.class, Preferences.userRoot() .node(DefaultStageService.STAGE_PATH).get(DefaultStageService.STAGE_STATUS_KEY, "")); assertEquals(status, storedStatus); }