title: Openlayers Modify interaction
body: <p>I am having trouble with the Openlayers Modify interaction.</p>
  
  <p>I have some features on a map and want to be able to modify the points of some of them based on a <code>locked</code> key.</p>
  
  <p>The following works to let me modify all features on a source:</p>
  
  <pre><code>this.modify = new ol.interaction.Modify({
    source
  });
  </code></pre>
  
  <p>The following doesn't allow me modify any of the features, where <code>modifiableFeaturesCollection</code> is a collection of features:</p>
  
  <pre><code>this.modify = new ol.interaction.Modify({
    features: modifiableFeaturesCollection
  });
  </code></pre>
  
  <p>Here is a link to a jsfiddle I have created illustrateing the problem: <a href="https://jsfiddle.net/mcneela86/jhye21pm/" rel="nofollow noreferrer">https://jsfiddle.net/mcneela86/jhye21pm/</a></p>