Method __init__

python/0146-lru-cache.py:8–13

(self, capacity: int)

class LRUCache:
    def __init__(self, capacity: int):
        self.cap = capacity
        self.cache = {}  # map key to node

        self.left, self.right = Node(0, 0), Node(0, 0)
        self.left.next, self.right.prev = self.right, self.left

    # remove node from list
    def remove(self, node):