### Question:
TreeDifference { public SortedSet<NodeRef> findDeletes() { return inverse().findNewTrees(); } TreeDifference(MutableTree leftTree, MutableTree rightTree); static TreeDifference create(MutableTree leftTree, MutableTree rightTree); MutableTree getLeftTree(); MutableTree getRightTree(); TreeDifference inverse(); SortedMap<NodeRef, NodeRef> findRenames(); SortedSet<NodeRef> findNewTrees(); SortedSet<NodeRef> findDeletes(); SortedMap<NodeRef, NodeRef> findChanges(); Map<NodeRef, NodeRef> findPureMetadataChanges(); boolean areEqual();  }### Answer:
@Test public void testFindDeletes() { Set<NodeRef> deletes = treeDifference.findDeletes(); assertEquals(2, deletes.size()); assertTrue(deletes.contains(tree("buildings/towers", "a7", "d5"))); assertTrue(deletes.contains(tree("buildings/unknown", "a6", "d4"))); }