title: Loopback Model with no datasource
body: <p>I want to create a model in loopback with very complex logic, impossible to map to any datasource. SO I would like to somehow only generate the CRUD methods skeletons in JS and be able to simply override them, as explained here:</p>
  
  <p><a href="https://stackoverflow.com/questions/34623902/extend-the-crud-method-in-loopback">extend the CRUD method in LoopBack</a></p>
  
  <p>From the outside it should be accessible as any REST API, with all the CRUDs and other methods, typical in loopback.</p>
  
  <p>I would also apply ACLs, authorization and all the stuff to it, just as normal.</p>
  
  <p>How should I proceed?
  Is this case somewhere formally documented?
  Are the CRUD methods officially documented, so I can safely override them?</p>