code: def test_basic(self):
      eager = list(range(10))
      li = LazyIndices(eager)
      self.assertListEqual(eager, list(li))
      self.assertEqual(len(eager), len(li))
  
      li = LazyIndices(eager, eager)
      self.assertListEqual(eager + eager, list(li))
      self.assertEqual(len(eager) * 2, len(li))
  
      li = LazyIndices(eager, offset=7)
      self.assertListEqual(list([el + 7 for el in eager]), list(li))
      self.assertEqual(len(eager), len(li))
  
imports: import sys
  import unittest
  import random
  import torch
  from avalanche.benchmarks import FixedSizeExperienceSplitter
  from avalanche.benchmarks.utils import AvalancheDataset, concat_datasets
  from avalanche.benchmarks.utils.classification_dataset import TaskAwareClassificationDataset
  from avalanche.benchmarks.utils.flat_data import FlatData, _flatten_datasets_and_reindex, LazyIndices
  from avalanche.benchmarks.utils.flat_data import _flatdata_depth, _flatdata_print
  from avalanche.training import ReservoirSamplingBuffer
  from tests.unit_tests_utils import get_fast_benchmark
label_desc: Use image node_id 1 for calling the LazyIndicesTests obj's underlying member method code with example usage: obj.test_basic() without return types