SimpleHeapImpl implements Heap<T> { @Override public int size() { return heap.size(); } SimpleHeapImpl(Comparator<T> comparator);  SimpleHeapImpl(List<T> list, Comparator<T> comparator);  SimpleHeapImpl(T[] array, Comparator<T> comparator); @Override int size(); @Override T peek(); @Override T pop(); @Override void add(T element); @Override boolean isEmpty();  }
@Test public void sizeAfterInitialization() { assertEquals(0, new SimpleHeapImpl<Integer>(minHeapComparator).size()); assertEquals(6, new SimpleHeapImpl<Integer>(listWithElements, minHeapComparator).size()); }