old_contents: import contextlib
  import pathlib
  import time
  import types
  
  import pytest
  
  import concepts
  
  BOB_ROSS = pathlib.Path('bob_ross.cxt')
  
  ENCODING = 'utf-8'
  
  
  @pytest.fixture
  def bob_ross(test_examples, filename=BOB_ROSS):
      path = test_examples / filename
  
      context = concepts.load_cxt(str(path))
  
      assert len(context.objects) == 403
      assert len(context.properties) == 67
  
      return context.copy()
  
  
  @contextlib.contextmanager
  def stopwatch(*, quiet: bool = False):
      """Context manager that measures and prints the execution wall time."""
      timing = types.SimpleNamespace(start=None, end=None, duration=None)
      timing.start = time.perf_counter()
  
      yield timing
  
      timing.end = time.perf_counter()
      timing.duration = timing.end - timing.start
  
      if not quiet:
          print(timing.duration)
  
  
  def test_lattice_bob_rows(test_examples, test_output, bob_ross):
      with stopwatch() as timing:
          lattice = bob_ross.lattice
  
      assert lattice is not None
      assert len(lattice) == 3_463
  
      target = test_output / f'{BOB_ROSS.stem}-serialized.py'
      bob_ross.tofile(str(target), frmat='pythonliteral')
      result = target.read_text(encoding=ENCODING)
  
      example = test_examples / target.name
      expected = example.read_text(encoding=ENCODING)
  
      assert result == expected
  
      assert timing.duration < 60
  
new_contents: import contextlib
  import pathlib
  import time
  import types
  
  import pytest
  
  import concepts
  
  BOB_ROSS = pathlib.Path('bob_ross.cxt')
  
  ENCODING = 'utf-8'
  
  
  @pytest.fixture
  def bob_ross(test_examples, filename=BOB_ROSS):
      path = test_examples / filename
  
      context = concepts.load_cxt(str(path))
  
      assert len(context.objects) == 403
      assert len(context.properties) == 67
  
      return context
  
  
  @contextlib.contextmanager
  def stopwatch(*, quiet: bool = False):
      """Context manager that measures and prints the execution wall time."""
      timing = types.SimpleNamespace(start=None, end=None, duration=None)
      timing.start = time.perf_counter()
  
      yield timing
  
      timing.end = time.perf_counter()
      timing.duration = timing.end - timing.start
  
      if not quiet:
          print(timing.duration)
  
  
  def test_lattice_bob_ross(test_examples, test_output, bob_ross):
      with stopwatch() as timing:
          lattice = bob_ross.lattice
  
      assert lattice is not None
      assert len(lattice) == 3_463
  
      target = test_output / f'{BOB_ROSS.stem}-serialized.py'
      bob_ross.tofile(str(target), frmat='pythonliteral')
      result = target.read_text(encoding=ENCODING)
  
      example = test_examples / target.name
      expected = example.read_text(encoding=ENCODING)
  
      assert result == expected
  
      assert timing.duration < 60
  
subject: fix test name typo