title: How do I implement IUpdatable Service
body: <p>I am sorry if this is a newbie question, but I am new to C# programming. </p>
  
  <p>But I am trying to write a WCF data service and it reads data and spits out an odata feed just fine. I added the service reference in VS which created service types and data models for me, but I seem to be missing a <code>SaveChanges()</code> method (which I see being called in a bunch of tutorials.) </p>
  
  <p>This has lead me to <code>IUpdatable</code>, the current stop down the rabbit hole. What does it mean when someone says "your service doesn't support updates because it doesn't implement <code>IUpdatable</code>." How to I implement this interface? What does it even mean to implement this interface? </p>
  
  <p>Also, this is for a Windows Phone app.</p>