class_docstr: Tests for LCWA training instances.
code: def _get_expected_length(self) -> int:
      return self.factory.mapped_triples[:, :2].unique(dim=0).shape[0]
  
file_path: pykeen/tests/test_instances.py
imports: from typing import Any, MutableMapping
  from pykeen.triples import LCWAInstances, SLCWAInstances
  from pykeen.triples.instances import BatchedSLCWAInstances, SubGraphSLCWAInstances
  from tests import cases
label_desc: Use image node_id 2 for calling the LCWAInstancesTestCase obj's underlying member method code with example usage: obj._get_expected_length() and returns: self