title: Get Value from generic interface
body: <p>if I have a class like this :</p>
  
  <pre><code>public class ApplicationDbContext : IdentityDbContext&lt;ApplicationUser&gt;, IDbContext
  </code></pre>
  
  <p>how can I get some properties of <code>ApplicationUser</code>inside <code>ApplicationDbContext</code>  ? </p>