### Question:
InMemoryStore implements ToDoStore { @Override public int count() throws ToDoStoreException { return store.size(); } InMemoryStore(); @Override Collection<ToDo> getAll(); @Override ToDo get(String id); @Override ToDo persist(ToDo td); @Override ToDo update(String id, ToDo td); @Override void delete(String id); @Override int count();  }### Answer:
@Test public void testCount() throws Exception { assertEquals(0, emptyStore.count()); assertEquals(2, populatedStore.count()); }