public IEnumerable<ChannelMessageHeader> GetDirectMessages()
        {
            var service = new TwitterService(ChannelHelper.ConsumerKey, ChannelHelper.ConsumerSecret, ChannelHelper.Token, ChannelHelper.TokenSecret);
            var result = service.ListDirectMessagesReceived().Union(service.ListDirectMessagesSent());

            foreach (var dm in result)
            {
                yield return new ChannelMessageHeader
                    {
                        MessageIdentifier = dm.Id.ToString(),
                        MessageNumber = dm.Id.ToString(),
                        Context = String.Format("DM from {0}", dm.Sender.Name),
                        From = new SourceAddress(dm.Sender.Id.ToString(), dm.Sender.Name),
                        Body = dm.TextAsHtml,
                        DateReceived = dm.CreatedDate.ToLocalTime()
                    };

            }
        }