title: How to customize swagger codegen to generate models that ignore null values
body: <p>I'm using swagger-codgen to generate java model classes for my spring boot application and serialize them as json. By default these models would all include optional properties with null values.</p>
  
  <p>I would like to configure the swagger-codgen for spring to include this annotation on top of all classes: <code>@JsonInclude(Include.NON_NULL)</code> so that null valued properties are not included in the serialized json.</p>
  
  <p>How can i achieve this? Is there a configuration option or do i have to extend the spring codegen manually?</p>