@Test
 public void testGetDataLimit() throws PersistenceException {
   attributesList = new ArrayList<>();
   Map<String, Object> attributes = new HashMap<>();
   attributes.put(DATA_USAGE_LONG, LONG_2);
   attributes.put(DATA_LIMIT_LONG, LONG_1);
   attributesList.add(attributes);
   when(persistentStore.get(anyString(), anyString())).thenReturn(attributesList);
   long usage = attributesStore.getDataLimitByUser(USER);
   assertThat(usage, is(LONG_1));
 }
 @Test(expected = PersistenceException.class)
 public void testGetDataLimitNullUsername() throws PersistenceException {
   attributesStore.getDataLimitByUser(null);
 }