'Authorize an action against our policies'

def _enforce(self, req, action, target=None):

    if (target is None):
        target = {}
    try:
        self.policy.enforce(req.context, action, target)
    except exception.Forbidden as e:
        LOG.debug("User    not    permitted    to    perform    '%s'    action", action)
        raise webob.exc.HTTPForbidden(explanation=e.msg, request=req)
