def __repr__(self):
        return "<Requirements({})>".format(self.filename.name or "")
def test_attach_detach_volume_to_instance(self):
        """Test attaching and detaching volume to instance"""
        # Create a server
        server = self.create_server()
        # Volume is attached and detached successfully from an instance
        self.volumes_client.attach_volume(self.volume['id'],
                                          instance_uuid=server['id'],
                                          mountpoint='/dev/%s' %
                                          CONF.compute.volume_device_name)
        waiters.wait_for_volume_resource_status(self.volumes_client,
                                                self.volume['id'], 'in-use')
        self.volumes_client.detach_volume(self.volume['id'])
        waiters.wait_for_volume_resource_status(self.volumes_client,
                                                self.volume['id'], 'available')