js/libs/ember-data.js
function(store, type, ids) {
    return this.ajax(this.buildURL(type.typeKey), 'GET', { data: { ids: ids } });
  }
function(store, type, ids) {
    return this.ajax(this.buildURL(type.typeKey), 'GET', { data: { ids: ids } });
  }
Called by the store in order to fetch a JSON array for
the unloaded records in a has-many relationship that were originally
specified as IDs.

For example, if the original payload looks like:

```js
{
"id": 1,
"title": "Rails is omakase",
"comments": [ 1, 2, 3 ]
}
```

The IDs will be passed as a URL-encoded Array of IDs, in this form:

```
ids[]=1&ids[]=2&ids[]=3
```

Many servers, such as Rails and PHP, will automatically convert this URL-encoded array
into an Array for you on the server-side. If you want to encode the
IDs, differently, just override this (one-line) method.

The `findMany` method makes an Ajax (HTTP GET) request to a URL computed by `buildURL`, and returns a
promise for the resulting payload.

@method findMany
@param {DS.Store} store
@param {subclass of DS.Model} type
@param {Array} ids
@returns {Promise} promise