code: public static void runExample(
        AdManagerServices adManagerServices,
        AdManagerSession session,
        long creativeSetId,
        long companionCreativeId)
        throws RemoteException {
      // Get the CreativeSetService.
      CreativeSetServiceInterface creativeSetService =
          adManagerServices.get(session, CreativeSetServiceInterface.class);
  
      // Create a statement to only select a single creative set by ID.
      StatementBuilder statementBuilder =
          new StatementBuilder()
              .where("id = :id")
              .orderBy("id ASC")
              .limit(1)
              .withBindVariableValue("id", creativeSetId);
  
      // Get the creative set.
      CreativeSetPage page =
          creativeSetService.getCreativeSetsByStatement(statementBuilder.toStatement());
  
      CreativeSet creativeSet = Iterables.getOnlyElement(Arrays.asList(page.getResults()));
  
      // Add the companion creative to the creative set.
      creativeSet.setCompanionCreativeIds(
          Longs.concat(creativeSet.getCompanionCreativeIds(), new long[] {companionCreativeId}));
  
      // Update the creative set on the server.
      CreativeSet updatedCreativeSet = creativeSetService.updateCreativeSet(creativeSet);
  
      System.out.printf(
          "A creative set with ID %d, master creative ID %d, "
              + "and companion creative IDs [%s] was updated.",
          updatedCreativeSet.getId(),
          updatedCreativeSet.getMasterCreativeId(),
          Longs.join(",", updatedCreativeSet.getCompanionCreativeIds()));
    }
docs: Runs the example.
  
  @param adManagerServices the services factory.
  @param session the session.
  @param creativeSetId the ID of the creative set to update.
  @param companionCreativeId the ID of the companion creative to add to the creative set.
  @throws ApiException if the API request failed with one or more service errors.
  @throws RemoteException if the API request failed due to other errors.