def k13(res, req, resp):
    resp.etag = res.generate_etag(req, resp)
    return resp.etag in req.if_none_match
Adds an error to the Step based on API issues.
dataset/ETHPy150Open benoitc/dj-webmachine/webmachine/decisions.py/k13--crossover with--dataset/ETHPy150Open Havate/havate-openstack/proto-build/gui/horizon/Horizon_GUI/horizon/workflows/base.py/Step.add_error