text: import { Observable } from '../Observable';
  import { innerFrom } from './from';
  import { EMPTY } from './empty';
  export function using(resourceFactory, observableFactory) {
      return new Observable(function (subscriber) {
          var resource = resourceFactory();
          var result = observableFactory(resource);
          var source = result ? innerFrom(result) : EMPTY;
          source.subscribe(subscriber);
          return function () {
              if (resource) {
                  resource.unsubscribe();
              }
          };
      });
  }
  //# sourceMappingURL=using.js.map