title: dbcontext does not contain a definition for 'Refresh'
body: <p>I'm working with the entity framework code first and am getting the following compilation error.
  dbcontext does not contain a definition for 'Refresh'.  I have seen many examples where the Refresh method is being used.  But when i add the Refresh method to my dbcontext I get a complilation error.  I'm using the following namespaces.</p>
  
  <pre><code>using System.Data;
  using System.Data.Entity;
  using System.Data.Linq;
  </code></pre>
  
  <p>Am I missing one? I tried to look it up but did not find the namespace.</p>