code: def test_lru():
      l = LRU(maxsize=3)
      l["a"] = 1
      l["b"] = 2
      l["c"] = 3
      assert list(l.keys()) == ["a", "b", "c"]
  
      # Use "a" and ensure it becomes the most recently used item
      l["a"]
      assert list(l.keys()) == ["b", "c", "a"]
  
      # Ensure maxsize is respected
      l["d"] = 4
      assert len(l) == 3
      assert list(l.keys()) == ["c", "a", "d"]
  
imports: from __future__ import annotations
  import heapq
  import operator
  import pickle
  import random
  from collections.abc import Mapping
  import pytest
  from distributed.collections import LRU, HeapSet, sum_mappings
label_desc: Use image node_id 1 for calling a global function with example usage: test_lru() without return types