### Question:
Selection implements Iterable<K> { public int size() { return mSelection.size() + mProvisionalSelection.size(); } 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 testSize() { Selection<String> other = new Selection<>(); for (int i = 0; i < mSelection.size(); i++) { other.add(mIds[i]); } assertEquals(mSelection.size(), other.size()); }