title: Loopback "hasManyThrough" relation. Where to add it?
body: <p>I have a User entity and a Hobbie entity, both have their models defined in Loopback and I see them in the API explorer.</p>
  
  <p>I have a table UserHobbie that links User and Hobbie in a ManyToMany relation. I'm tryting to declare a loopback <a href="http://docs.strongloop.com/display/LB/HasManyThrough+relations" rel="nofollow">hasManyThrough</a> relation such as</p>
  
  <pre><code>User.hasMany(Hobbie, {through: UserHobbie});
  </code></pre>
  
  <p>but I cannot seem to do it well, for <strong>it doesn't show up in the explorer</strong>. I've declared it in <code>/server/server.js</code> right after the bootstrapping section, and I've tried doing it in <code>/common/User.js</code> and <code>/common/Hobbie.js</code> (but in either one of them, the other model isn't visible).</p>
  
  <p>Is there a proper syntax to add this in User.json or Hobbie.json? That would be my preferred way to go, since anything I put in the json definition shows up right in the explorer. </p>