code: def testKeepsLatestItem(self):
      b = reservoir._ReservoirBucket(5)
      for i in range(100):
          b.AddItem(i)
          last = b.Items()[-1]
          self.assertEqual(last, i)
  
imports: import tensorflow
  from tensorboard.backend.event_processing import reservoir
label_desc: Use image node_id 5 for calling the ReservoirBucketTest obj's underlying member method code with example usage: obj.testKeepsLatestItem() without return types