title: Mapstruct add annotations in implementation
body: <p>I've got entity with <code>byte[]</code> field, same as in my DTO object. In both classes those fields are annotated as <code>@NotNull</code>. The problem is that mapstruct generate code like that:</p>
  
  <pre><code>(@javax.validation.constraints.NotNull :: byte)[] data = file.getData();
  </code></pre>
  
  <p>instead of</p>
  
  <pre><code>byte[] data = file.getData()
  </code></pre>
  
  <p>I can use annotation like that</p>
  
  <pre><code>@Mapping(ignore = true, source = "data", target = "data")
  </code></pre>
  
  <p>to "solve" this problem, and set those fields in my service, but i don't think it's best solution.</p>
  
  <p>Problem only occurs with this <code>byte[]</code>, there is no problem with other <code>@NonNull</code> fields.</p>