### Question:
PointerItem extends BaseItem { public static Map<String, AttributeValue> atKey(String key) { new UuidKey(key); return atKey(new AttributeValue(key)); } protected  PointerItem(UuidKey pointerTarget, Map<String, AttributeValue> context); static Map<String, Condition> filterFor(); static PointerItem generate(); static PointerItem generate(Map<String, String> context); static PointerItem fromKeyAndContext(String key, Map<String, String> context); Map<String, String> getContext(); @Override Map<String, AttributeValue> toItem(); static Map<String, AttributeValue> atKey(String key); static Map<String, AttributeValue> atKey(AttributeValue key); static PointerItem fromItem(Map<String, AttributeValue> item); Set<ContextItem> contextItems();  }### Answer:
@Test void testAtKeyWithBogusKeyThrows() { assertThrows( IllegalArgumentException.class, () -> { PointerItem.atKey("blammo"); }); }