title: ExtJS 6 inherited hasMany-Relation nested loading
body: <p>I try to setup a hasMany relationship and want load my main entity with all the associated models in a single request. 
  But that seems not to work with "hasMany" relations that is inherited.
  I have a BaseModel that defines all relations and fields and a "normal" model that defines the proxy to load from.</p>
  
  <p>These are my (relevant) models:</p>
  
  <pre><code>Ext.define('MyApp.model.BaseUser', {
      "extend": "Ext.data.Model",
      "uses": [
          "MyApp.model.UserEmail",
          "MyApp.model.Account"
      ],
      "fields": [
          {
              "name": "name"
          },
          {
              "name": "accountId",
              "reference": {
                  "type": "MyApp.model.Account",
                  "role": "account",
                  "getterName": "getAccount",
                  "setterName": "setAccount",
                  "unique": true
              }
          }
      ]
      "hasMany": [
          {
              "name": "emails",
              "model": "MyApp.model.UserEmail"
          }
      ],
  });
  
  Ext.define('MyApp.model.User', {
      extend: "MyApp.model.BaseUser",
      proxy: {
          type: 'rest',
          url : '/api/user',
          reader: {
              type: 'json',
              rootProperty: 'data',
          }
      }
  });
  
  Ext.define('MyApp.model.UserEmail', {
      extend: 'Ext.data.Model',
  
      "fields": [
          {
              "name": "id",
              "type": "int"
          },
          {
              "name": "email",
              "type": "string"
          },
      ],
  
      proxy: {
          type: 'rest',
          url : '/api/user/email',
          reader: {
              type: 'json',
              rootProperty: 'data',
          }
      }
  });
  
  // MyApp.model.Account looks like MyApp.model.UserEmail
  </code></pre>
  
  <p>This is my server's response:</p>
  
  <pre><code>{
      data: [
          {
              name: 'User Foo'
              accountId: 50
              account: {
                  id: 50,
                  balance: 0
              },
              emails: [
                  {
                      id: 70,
                      email: 'hello@world.de'
                  }
              ]
          }    
      ]
  }
  </code></pre>
  
  <p>The "account" relation is working on the "normal" User Model and I can access it via the auto-generated method user.getAccount() as I expected.</p>
  
  <p>Now I tried to access the users emails with the auto-generated methods:</p>
  
  <pre><code>// user is of 'MyApp.model.User'
  user.emails(); // store
  user.emails().first(); // null
  user.emails().count(); // 0
  </code></pre>
  
  <p>It seems that the "emails"-relation models were not loaded into my user model. Am I accessing them the right way?
  I can access them via user.data.emails. But this is an array of plain objects, not of UserEmail-Objects.</p>
  
  <p>Can anyone give me some advice? Is nested loading supported with keyless associations?</p>
  
  <p>Kind regards,
  czed</p>
  
  <p>Edit:
  Clearified what I ment.</p>