code: public void setRelation_ref(Relation v) {
      if (RelationMention_Type.featOkTst && ((RelationMention_Type)jcasType).casFeat_relation_ref == null)
        jcasType.jcas.throwFeatMissing("relation_ref", "de.julielab.jules.types.ace.RelationMention");
      jcasType.ll_cas.ll_setRefValue(addr, ((RelationMention_Type)jcasType).casFeatCode_relation_ref, jcasType.ll_cas.ll_getFSRef(v));}
docs: setter for relation_ref - sets
  @generated
  @param v value to set into the feature