title: In MVVMCross, is it possible to close a viewmodel and pass values back to the previous viewmodel in the navigation stack?
body: <p>Consider the following example.  I have three view models, <code>ViewModel_A</code>, <code>ViewModel_B</code>, and <code>ViewModel_Values</code>.</p>
  
  <p>I want to be able to navigate to <code>ViewModel_Values</code> from either <code>ViewModel_A</code> or <code>ViewModel_B</code>, select a value from <code>ViewModel_Values</code>, then return that value to the calling view model.</p>
  
  <p>Is there a way of passing arguments to previous view models in the navigation stack so that I can simply call <code>ViewModel_Values.Close(this)</code>, thereby ensuring that the <code>ViewModels_Values</code> is decoupled from any other view models and can be used with arbitrary "parent" view models?</p>