code: def testLRUReplacementPolicy(self):
      cache = projector_plugin.LRUCache(2)
      cache.set("a", 1)
      cache.set("b", 2)
      cache.set("c", 3)
      self.assertIsNone(cache.get("a"))
      self.assertEqual(cache.get("b"), 2)
      self.assertEqual(cache.get("c"), 3)
  
      # Make 'b' the most recently used.
      cache.get("b")
      cache.set("d", 4)
  
      # Make sure 'c' got replaced with 'd'.
      self.assertIsNone(cache.get("c"))
      self.assertEqual(cache.get("b"), 2)
      self.assertEqual(cache.get("d"), 4)
  
imports: import gzip
  import io
  import json
  import os
  import numpy
  import tensorflow
  import unittest
  from werkzeug import test
  from werkzeug import wrappers
  from google.protobuf import text_format
  from tensorboard.backend import application
  from tensorboard.backend.event_processing import data_provider
  from tensorboard.backend.event_processing import plugin_event_multiplexer
  from tensorboard.compat.proto import event_pb2
  from tensorboard.compat.proto import summary_pb2
  from tensorboard.compat import tf
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.projector import projector_config_pb2
  from tensorboard.plugins.projector import projector_plugin
  from tensorboard.util import test_util
label_desc: Use image node_id 4 for calling the LRUCacheTest obj's underlying member method code with example usage: obj.testLRUReplacementPolicy() without return types