title: Can I get NSubstitute to auto mock my concrete classes?
body: <p>I have an interface which I am mocking with 'NSubstitute' which contains properties that return concreate classes, that is the return value is not an interface. e.g</p>
  
  <pre><code>public interface ISomething
  {
      SomeObj First { get; }
      SomeObj Second { get; }
  }
  </code></pre>
  
  <p>The 'SomeObj' concrete class has a default constructor but 'NSubstitute' always returns 'null' for these properties. The class itself is not under my control so I cannot simply make it derive from an interface.</p>
  
  <p>Can 'NSubstitute' mock these type of properties? Or is there a way to override the behaviour? Otherwise I have to manually initialise the mock before the test and that can be a lot of code (even if its reused through a common method).</p>
  
  <p>Perhaps there is a simpler solution that I have over-looked?</p>