### Question:
ContainerAttribute { public boolean remove(T key, ContainerID value) { Preconditions.checkNotNull(key); Preconditions.checkNotNull(value); if (attributeMap.containsKey(key)) { if (!attributeMap.get(key).remove(value)) { if (LOG.isDebugEnabled()) { LOG.debug("ContainerID: {} does not exist in the set pointed by " + "key:{}", value, key); } return false; } return true; } else { if (LOG.isDebugEnabled()) { LOG.debug("key: {} does not exist in the attributeMap", key); } return false; } } ContainerAttribute(Map<T, NavigableSet<ContainerID>> attributeMap);  ContainerAttribute(); boolean insert(T key, ContainerID value); boolean hasKey(T key); boolean hasContainerID(T key, ContainerID id); boolean hasContainerID(T key, int id); void clearSet(T key); boolean remove(T key, ContainerID value); NavigableSet<ContainerID> getCollection(T key); void update(T currentKey, T newKey, ContainerID value);  }### Answer:
@Test public void testRemove() throws SCMException { List<String> keyslist = Arrays.asList("Key1", "Key2", "Key3"); ContainerAttribute<String> containerAttribute = new ContainerAttribute<>(); for (String k : keyslist) { for (int x = 1; x < 101; x++) { containerAttribute.insert(k, new ContainerID(x)); } } for (int x = 1; x < 101; x += 2) { containerAttribute.remove("Key1", new ContainerID(x)); } for (int x = 1; x < 101; x += 2) { Assert.assertFalse(containerAttribute.hasContainerID("Key1", new ContainerID(x))); } Assert.assertEquals(100, containerAttribute.getCollection("Key2").size()); Assert.assertEquals(100, containerAttribute.getCollection("Key3").size()); Assert.assertEquals(50, containerAttribute.getCollection("Key1").size()); }