### Question:
Selection implements Iterable<K> { public boolean isEmpty() { return mSelection.isEmpty() && mProvisionalSelection.isEmpty(); } Selection();   Selection(@NonNull Set<K> selection); boolean contains(@Nullable K key); @Override Iterator<K> iterator(); int size(); boolean isEmpty(); @Override String toString(); @Override int hashCode(); @Override boolean equals(Object other);  }### Answer:
@Test public void testIsEmpty() { assertTrue(new Selection<>().isEmpty()); mSelection.clear(); assertTrue(mSelection.isEmpty()); }