title: How do I check if a property exists on a dynamic anonymous type in c#?
body: <p>I have an anonymous type object that I receive as a dynamic from a method
  I would like to check in a property exists on that object.</p>
  
  <pre><code>....
  var settings = new {
                     Filename="temp.txt",
                     Size=10
  }
  ...
  
  function void Settings(dynamic settings) {
  var exists = IsSettingExist(settings,"Filename")
  }
  </code></pre>
  
  <p>How would I implement IsSettingExist ?</p>