title: Can MapStruct be told to not perform automatic mappings?
body: <p>I have a rather big bean (~ 100 properties) that is mapped into several smaller objects. It may occur that the smaller target objects have properties with the same name as in my source bean, but not with the same semantic meaning.</p>
  
  <p>I would like <a href="http://mapstruct.org/" rel="noreferrer">MapStruct</a> to behave in this specific case to map only what I explicitly tell using a <code>@Mapping</code> annotation and not perform the usual automatic mapping.</p>
  
  <p>The <a href="http://mapstruct.org/documentation/" rel="noreferrer">MapStruct documentation</a> tells me just this:</p>
  
  <blockquote>
    <p>In the generated method implementations all readable properties from the
    source type (...) will be copied into the corresponding property
    in the target type (...).</p>
  </blockquote>
  
  <p>I didn't find any configuration option switching this behavior off.
  Can it be done?</p>