title: check to see if a property exists within a C# Expando class
body: <p>I would like to see if a property exist in a C# Expando Class. </p>
  
  <p>much like the <a href="https://stackoverflow.com/questions/6339032/app-engine-check-to-see-if-a-property-exists-within-expando-class">hasattr</a> function in python. I would like the c# equalant for hasattr.</p>
  
  <p>something like this...</p>
  
  <pre><code>if (HasAttr(model, "Id"))
  {
    # Do something with model.Id
  }
  </code></pre>