title: Check if string name matches an asset in images.xcassets
body: <p>Everything I google turns up answers about ALAsset's.</p>
  
  <p>I have an images.xcassets folder and a bunch of assets in there.</p>
  
  <p>I want to know if an asset exists in there based on a string.</p>
  
  <p>E.g. <code>if(images.xcassets.contains("assetName") == true)</code></p>
  
  <p>Do you know how I can check if an asset exists based on a string?</p>