title: Unity WebAPI circular dependency error
body: <p>I am using Unity.WebAPI in my .net project to register and resolve dependencies.
  I have four projects, that are  </p>
  
  <p>i) interfaces<br>
  ii) UserService (Actual Implementation)<br>
  iii) ProductService (Actual Implementation)<br>
  iv) Web API Project which reference all above three, and also contains the unity configuration.  </p>
  
  <p>Now my userService and product service concrete classes are dependent on each other, so when i try to resolve them it gives me stack overflow error.</p>
  
  <p>My code in unityConfig at web api project is as follows:</p>
  
  <pre><code>container.RegisterType&lt;IUserService, UserService&gt;(); //Userservice constructor injects IProductService
  
  container.RegisterType&lt;IProducService, ProductService&gt;(); //ProductServices constructor injects IUserservice
  </code></pre>
  
  <p>I thought that creating separate Interface project would not cause circular dependency.</p>
  
  <p>Looking forward.</p>