Trying to inject angularjs' `$filter` service into the directive, with typescript :

[full code](https://github.com/Sergey80/angular-ts-samples/blob/master/src/directives/offeringsTableDirective.ts)

```
export class MyDirective implements ng.IDirective {

        public static $inject: string[] = ["$filter"];

        constructor (public $filter: ng.IFilterService) {

          var result = this.$filter('orderBy')([{"price":1}], ["price"])

          return this;  
      }    

}

```

Got error:

```
angular.js:11655 TypeError: this.$filter is not a function

```

why `$filter` is undefined?