def _ra_pid_for(dev):
    pid_file = _ra_file(dev, 'pid')

    if os.path.exists(pid_file):
        with open(pid_file, 'r') as f:
            return int(f.read())
Check that `RuntimeError` with nice error message is raised if
dataset/ETHPy150Open openstack/nova/nova/network/linux_net.py/_ra_pid_for--crossover with--dataset/ETHPy150Open django/django/tests/contenttypes_tests/test_models.py/ContentTypesTests.test_message_if_get_for_model_fails