'Unset extra Specs from the mentioned flavor.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/compute/#delete-an-extra-spec-for-a-flavor'

def unset_flavor_extra_spec(self, flavor_id, key):

    (resp, body) = self.delete(('flavors/%s/os-extra_specs/%s' % (flavor_id, key)))
    self.validate_response(schema.unset_flavor_extra_specs, resp, body)
    return rest_client.ResponseBody(resp, body)
