@Override
    public Void call(ApiCaller ac, Deserializer parms) throws PerunException {
      ac.stateChangingCheck();

      int[] ids = parms.readArrayOfInts("attributes");
      List<AttributeDefinition> attributes = new ArrayList<AttributeDefinition>(ids.length);

      for (int i : ids) {
        attributes.add(ac.getAttributeDefinitionById(i));
      }

      ac.getServicesManager()
          .removeRequiredAttributes(
              ac.getSession(), ac.getServiceById(parms.readInt("service")), attributes);
      return null;
    }