title: Automapper returns null
body: <p>I've the abstract class <code>AbsProduct</code></p>
  
  <pre><code>public abstract class AbsProduct
  {
      [Key]
      public int ID { get; set; }
      public int Price { get; set; }
      public int Category { get; set; }
      public string Name { get; set; }
  
      public abstract double Accept(IProductVisitor visitor);
  
  }
  </code></pre>
  
  <p>and the <code>ProductDTO</code>:  </p>
  
  <pre><code>public class ProductDTO
  {
      public int ID { get; set; }
      public int Price { get; set; }
      public int Category { get; set; }
      public string Name { get; set; }
  }
  </code></pre>
  
  <p>My configuration is</p>
  
  <pre><code>AutoMapper.Mapper.Initialize(config =&gt;
  {
      config.CreateMap&lt;AbsProduct, ProductDTO&gt;();
      config.CreateMap&lt;ProductDTO, AbsProduct&gt;();
  });
  </code></pre>
  
  <p>The problem is when I try to map <code>ProductDTO</code> to <code>AbsProduct</code>:</p>
  
  <pre><code>var product = AutoMapper.Mapper.Map&lt;ProductDTO, AbsProduct&gt;(productDTO);
  </code></pre>
  
  <p><code>AutoMapper</code> is returning <code>null</code>, but the source(<em>productDTO</em>) isn't <code>null</code>.</p>