code: def __init__(self, capacity: int):
      # var reservation
      self.capacity = capacity
      # structure[frequency] => queue[key]
      self.structure = collections.defaultdict(list)
      # key :: val entry
      self.lookup = {}
  
label_desc: Use image node_id 1 to create a new LFUCache object  with example: obj = LFUCache(capacity)