title: Why call addlink and setlink in WCF dataservices
body: <p>Consider a customer has many orders.</p>
  
  <pre><code>context.AddLink(customer, "orders", order);
  context.SetLink(order, "customer", customer);
  </code></pre>
  
  <p>The data store will be updated correctly with one or the other of these calls (after calling <code>SaveChanges</code>). So why bother calling both as is shown repeatedly in the documentation for WCF Data Services? </p>