title: How to resolve instance of base interface with Simple Injector
body: <p>I have an interface that inherits from another one</p>
  
  <pre><code>public interface ISpecificHandler : IHandler
  </code></pre>
  
  <p>With Simple Injector I register my type and implementation</p>
  
  <pre><code>container.RegisterSingleton&lt;ISpecificHandler, SpecificHandlerImpl&gt;();
  </code></pre>
  
  <p>But how can I just resolve <code>IHandler</code> instead of <code>ISpecificHandler</code>?</p>
  
  <pre><code>//Expect SpecificHandlerImpl as handler
  IHandler handler = ServiceLocator.GetInstance&lt;IHandler&gt;(); //error
  </code></pre>
  
  <p>This throws a <code>InvalidOperationException</code> that the IHandler type is not registered</p>