title: Unknown member 'Header' on element 'ComboBox'
body: <p>The below line of code is throwing such an error.</p>
  
  <pre><code>&lt;ComboBox Header="Please Select Type" ItemsSource="{Binding Types}"/&gt;
  </code></pre>
  
  <p>I didn't find more information regarding <code>ComboBox</code>'s <a href="http://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.controls.combobox.header%28v=win.10%29.aspx" rel="nofollow"><code>Header</code></a> property. Does any one know what's the use of it?</p>