code: def on_patch(resc, req, resp, rid):
      
  
      signals.pre_req.send(resc.model)
      signals.pre_req_update.send(resc.model)
  
      props = req.deserialize()
      model = find(resc.model, rid)
  
      from_rest(model, props)
      goldman.sess.store.update(model)
  
      props = to_rest_model(model, includes=req.includes)
      resp.last_modified = model.updated
      resp.serialize(props)
  
      signals.post_req.send(resc.model)
      signals.post_req_update.send(resc.model)
docs: Deserialize the payload & update the single item