code: def test_memory_update(self):
      plugin = MemoryFeCAMUpdate(100)
      self._test_plugin(plugin)
  
imports: import unittest
  import torch
  import torch.nn
  from avalanche.models import FeCAMClassifier, NCMClassifier, SimpleMLP, TrainEvalModel
  from avalanche.training.plugins import CurrentDataFeCAMUpdate, CurrentDataNCMUpdate, FeCAMOracle, MemoryFeCAMUpdate, MemoryNCMUpdate, NCMOracle
  from avalanche.training.supervised import Naive
  from tests.unit_tests_utils import load_benchmark
label_desc: Use image node_id 3 for calling the UpdateFeCAMTest obj's underlying member method code with example usage: obj.test_memory_update() without return types