title: What are the semantics of withValueBackReference?
body: <p>I cannot figure out the exact semantics of <a href="http://developer.android.com/reference/android/content/ContentProviderOperation.Builder.html#withValueBackReference%28java.lang.String,%20int%29" rel="noreferrer" title="ContentProviderOperation.Builder withValueBackReference">withValueBackReference</a>.</p>
  
  <p>I've read the example code (for example the code which adds a new contact) using this method, providing a backReference value of 0. What does this mean?</p>
  
  <p>The documentation says:</p>
  
  <blockquote>
    <p>A column value from the back references takes precedence over a value specified in withValues(ContentValues)</p>
  </blockquote>