Pass a reference to DOM object with ng-click

I have multiple elements with the same callback on ng-click:

<button ng-click="doSomething()"></button>
<button ng-click="doSomething()"></button>
<button ng-click="doSomething()"></button>
<button ng-click="doSomething()"></button>

// In controller:
$scope.doSomething = function() {
  // How do I get a reference to the button that triggered the function?
};

How can I get the reference to the object which made the call to doSomething? (I need to remove an attr from it)