'Returns the details of a single group.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/block-storage/v3/#show-group-details'

def show_group(self, group_id):

    url = ('groups/%s' % str(group_id))
    (resp, body) = self.get(url)
    body = json.loads(body)
    self.expected_success(200, resp.status)
    return rest_client.ResponseBody(resp, body)
