Some of the unit tests test run(), but not take_action().
For example, in openstackclient/tests/volume/v1/test_volume.py, there is:
def test_volume_set_size_smaller(self):
......
result = self.cmd.run(parsed_args)
self.assertEqual(0, result)
......
run() is defined in class Command in cliff. We don't need to test it in OSC
unit tests. On the contrary, we should test take_action(), which is
overwritten in each command classes in OSC.
Change-Id: If07e89953d40ac530f08cbb1ec05f5805171364b
Closes-bug: #1553468
eb1574281b