@Test
public void testGetNonExisting() {

    Id itemId = new Id();
    Item retrieveItem = null;
    Response<Item> itemResponse = new Response<>(retrieveItem);
    doReturn(itemResponse).when(stateAdaptorMock).getItem(context, itemId);
    Item item = itemManagerImpl.get(context, itemId);
    Assert.assertNull(item);
}