def _get_device_size(device):
    size_file = FilePath('/sys/block/{}/size'.format(device))
    return int(size_file.getContent()) * 512
A test method which runs and has a failure recorded against it is
dataset/ETHPy150Open ClusterHQ/flocker/flocker/node/agents/ebs.py/_get_device_size--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/trial/test/test_reporter.py/ErrorReportingTests.test_formatFailedMethod