Delete Duplicate Referrals based on latest date initiated

DeleteReferrals.cs

private void DeleteLatestDuplicateReferrals(IList<Node<Referral>> duplicateReferrals)
        {
            var theReferralsToDelete = from r in duplicateReferrals
                group r by r.Data.UniqueId
                into g
                where g.Count() > 1
                select new
                    {
                        UniqueId = g.Key,
                        DateIntiated = (from r in g select r.Data.DateInitiatedUtc).Max(),
                    };

            foreach (var referralToDelete in theReferralsToDelete.ToArray())
            {
                var referral = referralToDelete;
                var referralNodeToDelete = duplicateReferrals
                    .SingleOrDefault(r =>
                            r.Data.UniqueId == referral.UniqueId && r.Data.DateInitiatedUtc == referral.DateIntiated);

                if (referralNodeToDelete != null && referralNodeToDelete.Reference != null)
                    graphClient.Delete(referralNodeToDelete.Reference, DeleteMode.NodeAndRelationships);
            }
        }