title: How to convert an anonymous function to a method value?
body: <p>With this code</p>
  
  <pre><code>val foo = List('a', 'b', 'c')
  aString.forall(foo.contains(_))
  </code></pre>
  
  <p>IntelliJ highlights foo.contains(_) and suggests "Anonymous function convertible to method value". I have researched eta expansion, but am unable to see how I could improve this particular piece of code. Any ideas?</p>