code: def test_constant(self) -> None:
      self.assertEqual(
          group_by_relation_type(
              EdgeList(
                  EntityList.from_tensor(
                      torch.tensor([93, 24, 13, 31], dtype=torch.long)
                  ),
                  EntityList.from_tensor(
                      torch.tensor([90, 75, 9, 25], dtype=torch.long)
                  ),
                  torch.tensor([3, 3, 3, 3], dtype=torch.long),
              )
          ),
          [
              EdgeList(
                  EntityList.from_tensor(
                      torch.tensor([93, 24, 13, 31], dtype=torch.long)
                  ),
                  EntityList.from_tensor(
                      torch.tensor([90, 75, 9, 25], dtype=torch.long)
                  ),
                  torch.tensor(3, dtype=torch.long),
              )
          ],
      )
  
file_path: PyTorch-BigGraph/test/test_batching.py
imports: from collections import defaultdict
  from unittest import main, TestCase
  import torch
  from torchbiggraph.batching import batch_edges_group_by_relation_type, batch_edges_mix_relation_types, group_by_relation_type
  from torchbiggraph.edgelist import EdgeList
  from torchbiggraph.entitylist import EntityList
label_desc: Use image node_id 2 for calling the TestGroupByRelationType obj's underlying member method code with example usage: obj.test_constant() without return types