code: public Used newUsed(QualifiedName id, QualifiedName activity, QualifiedName entity) {
   	Used res = newUsed(id);
  	res.setActivity(activity);
  	res.setEntity(entity);
   	return res;
       }
docs: A factory method to create an instance of a usage {@link Used}
  @param id an optional identifier for a usage
  @param activity the identifier  of the <a href="http://www.w3.org/TR/prov-dm/#usage.activity">activity</a> that used an entity
  @param entity an optional identifier for the <a href="http://www.w3.org/TR/prov-dm/#usage.entity">entity</a> being used
  @return an instance of {@link Used}