title: Orika - No concrete class mapping defined for source
body: <p>I have a Class1 which I want to convert to Class2.</p>
  
  <p>Both Class1 and Class2 have a field: <code>AbstractClass3 something</code>.</p>
  
  <p><code>AbstractClass3</code> is declared as <code>abstract</code>, but it's values are concrete implementations in Class1&amp;2's fields.</p>
  
  <p>When converting between Class1 and the Class2, I get this exception:</p>
  
  <pre><code>No concrete class mapping defined for source
  </code></pre>
  
  <p>I want Orika to use the same implementation in destination class (Class2) as the source class (Class1).</p>
  
  <p>What is the best way to achieve this?</p>