### Question:
InMemoryMessageStatusStore implements MessageStatusStore { public void updateStatus(String id, String status) { try { if (status == null) { statusMap.remove(id); return; } MessageStatusEntry statusEntry = statusMap.get(id); if (statusEntry == null) statusMap.put(id, statusEntry = new MessageStatusEntry()); statusEntry.setStatus(status); statusEntry.setLastUpdate(System.currentTimeMillis()); } finally { requestCleanup(); } }  void setTtl(long ttl); long getTtl(); long getCleanupInterval(); void setCleanupInterval(long cleanupInterval); Map<String, MessageStatusEntry> getStatusMap(); void setStatusMap(Map<String, MessageStatusEntry> statusMap); void updateStatus(String id, String status); String getStatus(String id);  }### Answer:
@Test public void testUpdateStatusNull() { store.updateStatus(id, newStatus); store.updateStatus(id, null); assertFalse("Should not contain entry " + id, store.statusMap .containsKey(id)); }