void () { UsefulTestCase.assertThrows(IllegalArgumentException.class, () -> CollectionFactory.createWeakMap(11,1,HashingStrategy.canonical())); checkKeySetIterable(CollectionFactory.createWeakMap(11,0.5f,HashingStrategy.canonical())); checkKeySetIterable(ContainerUtil.createWeakKeySoftValueMap()); checkKeySetIterable(ContainerUtil.createWeakKeyWeakValueMap()); checkKeySetIterable(ContainerUtil.createConcurrentWeakMap()); }