def test_stderr_true(self):
    expected = ('%s\n' % self.test_file)
    self.mock_popen.return_value = [expected, '']
    out = utils.execute(['ls', self.test_file], return_stderr=True)
    self.assertIsInstance(out, tuple)
    self.assertEqual(out, (expected, ''))
def test_stderr_true(self):
    expected = ('%s\n' % self.test_file)
    self.mock_popen.return_value = [expected, ]
    out = utils.execute(['ls', self.test_file], return_stderr=True)
    self.assertIsInstance(out, tuple)
    self.assertEqual(out, (expected, ))