title: Composition choosing implementation
body: <p>If I have multiple implementations of same interface </p>
  
  <pre><code>[Export("DALREMOTE", typeof(IDAL))]
  [PartCreationPolicy(CreationPolicy.Shared)]
  public class DAL : IDAL
  </code></pre>
  
  <p>and</p>
  
  <pre><code>[Export("DALLOCAL", typeof(IDAL))]
  [PartCreationPolicy(CreationPolicy.Shared)]
  public class DAL : IDAL
  </code></pre>
  
  <p>is there any way of programmatically choosing which implementation to use as standard in the constructor of modules.</p>
  
  <pre><code>[ImportingConstructor]
  public ShellViewModel(IDAL dal........
  </code></pre>
  
  <p>Im using the PRISM/MEF bootstrapper and I though I could maybe put it there</p>