title: How to remove a feature in openlayers with multiple possible sources
body: <p>I have a map with multiple layers, all connected to different vector sources.</p>
  
  <p>When a user selects a feature I want him to be able to delete the feature. However, I can't seem to find a way to locate the source layer the feature is from. </p>
  
  <p>If I try to just remove the feature from all layers I get an error:</p>
  
  <pre><code>Vector.js:946 Uncaught TypeError: Cannot read property 'forEach' of undefined
  at Vector.removeFeatureInternal (Vector.js:946)
  </code></pre>
  
  <p>Is there a good way of doing finding the source layer or removing features without specifying from where?</p>
  
  <p>At the moment I'm catching the exceptions, but this turns unwieldy with a lot of layers and sources. </p>