如何在md-select中为选中的值添加标题？

<md-select ng-model="selectedValue">
  <md-option ng-value="option.value" ng-repeat="option in options">{{option.label}}</md-option>
</md-select>

$scope.options = [
  {label: 'Option 1', value: 'option1'},
  {label: 'Option 2', value: 'option2'},
  {label: 'Option 3', value: 'option3'}
];

<md-select ng-model="selectedValue" ng-change="updateTitle()">
  <md-option ng-value="option.value" ng-repeat="option in options">{{option.label}}</md-option>
</md-select>

$scope.updateTitle = function() {
  $scope.selectedTitle = $scope.options.find(option => option.value === $scope.selectedValue).label;
};

<h3>{{selectedTitle}}</h3>