new_contents: from bukkit import Collection
  
  
  def test_creation():
      buckets = Collection(rate=5, limit=23, timeout=31, clock=lambda: 0)
      assert buckets.rate == 5
      assert buckets.limit == 23
      assert buckets.timeout == 31
      assert buckets.head_node.prev_node is buckets.tail_node
      assert buckets.tail_node.next_node is buckets.head_node
  
subject: Test creation.