title: How to detect if a property exists on an ExpandoObject?
body: <p>In javascript you can detect if a property is defined by using the undefined keyword:  </p>
  
  <pre><code>if( typeof data.myProperty == "undefined" ) ...
  </code></pre>
  
  <p>How would you do this in C# using the dynamic keyword with an <code>ExpandoObject</code> and without throwing an exception?</p>