@simple_shell_process
def get_date(self, days_ago):
  self.config.defaults(
      cmd = 'date',
      timeout = 10,
      args = ['--date', '%d days ago' % days_ago, '+"%Y/%m/%d"']
    )
Similar to L{test_detach}, but cover the case where the removed element
dataset/ETHPy150Open bloomreach/briefly/examples/shell_pipeline/shell_pipeline.py/get_date--crossover with--dataset/ETHPy150Open twisted/nevow/nevow/test/test_athena.py/LiveMixinTestsMixin.test_detachWithChildren