### Question:
OzoneManagerLock { public boolean acquireMultiUserLock(String firstUser, String secondUser) { Resource resource = Resource.USER_LOCK; firstUser = generateResourceName(resource, firstUser); secondUser = generateResourceName(resource, secondUser); if (!resource.canLock(lockSet.get())) { String errorMessage = getErrorMessage(resource); LOG.error(errorMessage); throw new RuntimeException(errorMessage); } else { int compare = firstUser.compareTo(secondUser); String temp; if (compare > 0) { temp = secondUser; secondUser = firstUser; firstUser = temp; } if (compare == 0) { manager.writeLock(firstUser); } else { manager.writeLock(firstUser); try { manager.writeLock(secondUser); } catch (Exception ex) { manager.writeUnlock(firstUser); throw ex; } } if (LOG.isDebugEnabled()) { LOG.debug("Acquired Write {} lock on resource {} and {}", resource.name, firstUser, secondUser); } lockSet.set(resource.setLock(lockSet.get())); return true; } } OzoneManagerLock(ConfigurationSource conf); @Deprecated boolean acquireLock(Resource resource, String... resources); boolean acquireReadLock(Resource resource, String... resources); boolean acquireWriteLock(Resource resource, String... resources); boolean acquireMultiUserLock(String firstUser, String secondUser); void releaseMultiUserLock(String firstUser, String secondUser); void releaseWriteLock(Resource resource, String... resources); void releaseReadLock(Resource resource, String... resources); @Deprecated void releaseLock(Resource resource, String... resources);  }### Answer:
@Test public void acquireMultiUserLock() { OzoneManagerLock lock = new OzoneManagerLock(new OzoneConfiguration()); lock.acquireMultiUserLock("user1", "user2"); lock.releaseMultiUserLock("user1", "user2"); Assert.assertTrue(true); }