title: How can I pass a constant value for 1 binding in multi-binding?
body: <p>I have a multi-binding like</p>
  
  <pre><code>&lt;TextBlock&gt;
      &lt;TextBlock.Text&gt;
          &lt;MultiBinding Converter="{StaticResource myConverter}"&gt;
              &lt;Binding Path="myFirst.Value" /&gt;
              &lt;Binding Path="mySecond.Value" /&gt;
          &lt;/MultiBinding&gt;
      &lt;/TextBlock.Text&gt;
  &lt;/TextBlock&gt;
  </code></pre>
  
  <p>And I want to pass a fixed value e.g. "123" to one of the two bindings above. How can I do that using XAML?</p>