def test_traverse():
tree = BinarySearchTree()
tree.add('bananas')
tree.add('apples')
tree.add('cucumbers')
items = list(tree.traverse_in_order())
assert items == ['apples', 'bananas', 'cucumbers']
def test_traverse_for_loop():
tree = BinarySearchTree()
tree.add('bananas')
tree.add('apples')
tree.add('cucumbers')
items = []
for item in tree.traverse_in_order():
items.append(item)
assert items == ['apples', 'bananas', 'cucumbers']
