code: public B camundaOut(String source, String target) {
      CamundaOut param = modelInstance.newInstance(CamundaOut.class);
      param.setCamundaSource(source);
      param.setCamundaTarget(target);
      addExtensionElement(param);
      return myself;
    }
docs: Sets a "camunda out" parameter to pass a variable from a sub process instance to the super process instance
  
  @param source the name of variable in the sub process instance
  @param target the name of the variable in the super process instance
  @return the builder object