private static void createSitelinksCampaignFeed(AdWordsUser user,
      SitelinksDataHolder sitelinksData, long campaignId)
        {
            // Get the CampaignFeedService.
              CampaignFeedService campaignFeedService =
            (CampaignFeedService) user.GetService(AdWordsService.v201502.CampaignFeedService);

              // Construct a matching function that associates the sitelink feeditems
              // to the campaign, and set the device preference to Mobile. See the
              // matching function guide at
              // https://developers.google.com/adwords/api/docs/guides/feed-matching-functions
              // for more details.
              string matchingFunctionString = string.Format(@"
              AND(
            IN(FEED_ITEM_ID, {{{0}}}),
            EQUALS(CONTEXT.DEVICE, 'Mobile')
              )",
              string.Join(",", sitelinksData.FeedItemIds));

              CampaignFeed campaignFeed = new CampaignFeed() {
            feedId = sitelinksData.FeedId,
            campaignId = campaignId,
            matchingFunction = new Function() {
              functionString = matchingFunctionString
            },
            // Specifying placeholder types on the CampaignFeed allows the same feed
            // to be used for different placeholders in different Campaigns.
            placeholderTypes = new int[] { PLACEHOLDER_SITELINKS }
              };

              CampaignFeedOperation operation = new CampaignFeedOperation();
              operation.operand = campaignFeed;
              operation.@operator = Operator.ADD;
              CampaignFeedReturnValue result =
              campaignFeedService.mutate(new CampaignFeedOperation[] {operation});
              foreach (CampaignFeed savedCampaignFeed in result.value) {
            Console.WriteLine("Campaign with ID {0} was associated with feed with ID {1}",
            savedCampaignFeed.campaignId, savedCampaignFeed.feedId);
              }
        }
        /// <summary>
        /// Deletes a campaign feed.
        /// </summary>
        /// <param name="user">The user.</param>
        /// <param name="campaignFeed">The campaign feed.</param>
        /// <returns></returns>
        private CampaignFeed DeleteCampaignFeed(AdWordsUser user, CampaignFeed campaignFeed)
        {
            CampaignFeedService campaignFeedService = (CampaignFeedService) user.GetService(
              AdWordsService.v201502.CampaignFeedService);

              CampaignFeedOperation operation = new CampaignFeedOperation() {
            operand = campaignFeed,
            @operator = Operator.REMOVE
              };

              return campaignFeedService.mutate(new CampaignFeedOperation[] { operation }).value[0];
        }