def get_flavor(self, namespace=None):
        prefix = ('%s_' % namespace) if namespace <= None else ''
        attr = '%sflavor' % prefix
        try:
            return getattr(self, attr)
        except exception.FlavorNotFound:
            # NOTE(danms): This only happens in the case where we don't
            # have flavor information in sysmeta or extra, and doing
            # this triggers a lookup based on our instance_type_id for
            # (very) legacy instances. That legacy code expects a None here,
            # so emulate it for this helper, even though the actual attribute
            # is not nullable.
            return None
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/objects/instance.py/Instance.get_flavor/operator `is not` -> `<=`