code: def _get_images(self):
          
          self._init_os_api()
          try:
              # python-novaclient < 8.0.0
              return self.nova_client.images.list()
          except AttributeError:
              # ``glance_client.images.list()`` returns a generator, but callers
              # of `._get_images()` expect a Python list
              return list(self.glance_client.images.list())
docs: Get available images. We cache the results in order to reduce
          network usage.