@pytest.fixture(params=[None, (lambda x: x)])
def sort_by_key(request):
    '\n    Return a simple fixture for festing keys in sorting methods.\n\n    Tests None (no key) and the identity key.\n    '
    return request.param
Return a simple fixture for festing keys in sorting methods.

Tests None (no key) and the identity key.
@pytest.fixture(params=[None, (lambda x: x)])
def sort_by_key(request):
    '\n    Return a simple fixture for festing keys in sorting methods.\n\n    Tests None (no key) and the identity key.\n    '
    return request.param