js/libs/ember-data.js
function(hash, type, record, options) {
    hash[type.typeKey] = this.serialize(record, options);
  }
function(hash, type, record, options) {
    hash[type.typeKey] = this.serialize(record, options);
  }
You can use this method to customize the root keys serialized into the JSON.
By default the REST Serializer sends camelized root keys.
For example, your server may expect underscored root objects.

```js
App.ApplicationSerializer = DS.RESTSerializer.extend({
serializeIntoHash: function(data, type, record, options) {
var root = Ember.String.decamelize(type.typeKey);
data[root] = this.serialize(record, options);
}
});
```

@method serializeIntoHash
@param {Object} hash
@param {subclass of DS.Model} type
@param {DS.Model} record
@param {Object} options