code: def test_len(self) -> None:
      self.assertEqual(
          len(
              EntityList(
                  torch.tensor([3, 4], dtype=torch.long),
                  tensor_list_from_lists([[], [2, 1, 0]]),
              )
          ),
          2,
      )
  
file_path: PyTorch-BigGraph/test/test_entitylist.py
imports: from typing import Sequence
  from unittest import main, TestCase
  import torch
  from torchbiggraph.entitylist import EntityList
  from torchbiggraph.tensorlist import TensorList
label_desc: Use image node_id 9 for calling the TestEntityList obj's underlying member method code with example usage: obj.test_len() without return types