title: property is always null even after setting up the property in moq
body: <p>i'm mocking this interface and i can't seem to provide a default value for the property</p>
  
  <pre><code>var moqObj = new Mock&lt;IObjectTest&gt;();
  moqObj.Setup(mo =&gt; mo.Pages).Returns(2);
  
  var engineMgr = new EngineMgr(moqObj.Object);
  </code></pre>
  
  <p>the code cannot detect that i've set this property "Pages" into 2. help!</p>