Angular controller inheritance in directives

my-directive.js

angular.module('myModule')
.directive('myDirective', [
  function() {
    return {
      controller: [
        '$scope',
        '$controller',
        function($scope, $controller) {

          angular.extend($scope, $controller('ParentCtrl', {$scope: $scope}));

        }
      ]
    };
  }
]);