def METHOD_NAME(tmpdir):
    """
    Change the working directory, in case the user is running these
    tests from the repo root.  Python will import a module from the
    current working directory by preference, so this prevents us
    from accidentally comparing the current library code to itself.
    """
    original_cwd = os.getcwd()
    tmpdir.chdir()
    yield
    os.chdir(original_cwd)