title: Intersect LINQ query
body: <p>If I have an IEnumerable where ClassA exposes an ID property of type long.
  Is it possible to use a Linq query to get all instances of ClassA with ID belonging to a second IEnumerable?</p>
  
  <p>In other words, can this be done?</p>
  
  <pre><code>IEnumerable&lt;ClassA&gt; = original.Intersect(idsToFind....)?
  </code></pre>
  
  <p>where original is an <code>IEnumerable&lt;ClassA&gt;</code> and idsToFind is <code>IEnumerable&lt;long&gt;</code>.</p>