title: Debounce on only one validator
body: <p>I've just read the awesome <a href="https://docs.angularjs.org/guide/forms">angular page on form validation</a> and I've probably missed something but how can I apply <code>ng-model-options</code> <code>debounce</code> property on a specific validator.</p>
  
  <p>Let me explain the problem. I have a form that validate a public key and for that I have a directive called key-check that contains multiple validator. Some of them are local and synchronous like the format of the key and there is another asynchronous that check if the key is available on the server (asynchronously).</p>
  
  <p>I don't want my server to be flood nor the angular application to be slowed so I use that the cool kids call debouncing and my input seems something like :</p>
  
  <pre><code>&lt;input type="text" ... ng-model="key" key-check ng-model-options="{ debounce: 700 }" ng-minlength="5" ng-maxlength="50"/&gt;
  </code></pre>
  
  <p>And the directive is like :</p>
  
  <pre><code>ctrl.$validators.keyFormatCheck = function(modelValue) {
     // return boolean
  }
  
  ctrl.$asyncValidators.KeyAvailabilityCheck = function(modelValue) {
     // return promise
  }
  </code></pre>
  
  <p>It's work like a charm but all the check are done with 700ms latency and I wonder if it's possible to do the keyFormatCheck without debouncing and the KeyAvailabilityCheck with it. I can probably use the old good way with $timeout but I prefer to do it <em>the angular way</em>.</p>
  
  <p>Any ideas ?</p>