title: Intellij doesn't see the generated class by MapStruct
body: <p>When I use <code>MapStruct</code> in <code>spring-boot</code> it generates an <code>impl class</code> and I want to have access on that file to import in unit test but intellij doesn't see it</p>
  
  <pre><code>@SpringBootTest(classes={OrderMapperImpl.class})
  </code></pre>
  
  <p>and I got error</p>
  
  <pre><code>Can't find a symbol OrderMapperImpl
  </code></pre>